D1/AS1 Access Routes

Stairway type

The design

Risers

15

Table 6

Riser

183.7mm

Table 6

Tread, at least

280mm

Table 6

Pitch at that tread

33.27°

Table 6

Intermediate landings

0

Table 7

1. Risers

   15 risers, the fewest Table 6 allows for 2755 mm (2.755 m) on a Main private stairway. Add one to make it shallower.

   4.1.1, Table 6

2. Riser height

   183.7 mm each, over 15 risers, against a maximum of 190 mm.

   4.1.1, Table 6

3. Tread depth

   No less than 280 mm, nosing included. With the nosing taken off, the going is 280 mm, and the pitch line slope is 33.27°, against a maximum of 37°.

   4.1.1, Table 6, Figure 12, Definitions p.15

4. Nosing

   No nosing: the going is the full 280 mm tread depth.

   4.1.2, Figure 12, 4.1.6 b)

5. Landings

   None between floors: 2755 mm (2.755 m) is within the 4000 mm (4 m) Table 7 allows between landings for Main private stairways. Landings at top and bottom still.

   4.3.1, 4.3.2, Table 7

6. Landing size

   No less than 900 mm long, and no narrower than the stair it serves (1000 mm (1 m)).

   4.3.3, 4.3.4

1. Sides needing a handrail

   At least one side: 1000 mm (1 m) wide, up to the 2000 mm (2 m) that 6.0.1 sets, with 15 risers.

   6.0.1

D1 only sets the handrail. What fills the side below it is F4/AS1's. Where someone could fall 1 m or more, the side needs a barrier. In housing, or anywhere children under 6 are likely, no gap in it may let a 100 mm sphere through, and the triangle between the tread, riser and bottom rail must not let a 150 mm sphere through. Elsewhere, gaps may be up to 300 mm between balusters or 460 mm between rails. F4/AS1 Figures 1–4 show barriers a small child can't easily climb. NZBC F4.3.1, F4/AS1 1.2.1, 1.2.2, Figures 1–4

1. Triangle under the bottom rail

   With a 183.7 mm riser and a 280 mm going, a bottom rail 100 mm above the pitch line, where F4/AS1 Figure 4 draws it, leaves a triangle a 213 mm sphere passes through, where F4/AS1 1.2.1 c) allows under 150 mm. The sphere is the limit that governs, not the figure's 100 mm.

   F4/AS1 1.2.1 c), F4/AS1 Figure 4

2. How close the rail has to sit

   On this stair the bottom rail has to sit no more than 24 mm above the pitch line, square to it, to keep the triangle under 150 mm, against the 100 mm F4/AS1 Figure 4 draws.

   F4/AS1 1.2.1 c), F4/AS1 Figure 4

3. Figure 4's pitch

   This stair's pitch is 33.3°, not steeper than the 35° F4/AS1 Figure 4 is drawn at. Read as the figure's condition, its raking rails are not the construction for this stair. The reading is ours, and the COMMENT under F4/AS1 1.2.1 says near-horizontal rails are easily climbed.

   F4/AS1 Figure 4, F4/AS1 1.2.1 COMMENT 3

Type of ramp

The design

Slope, 1 in

12

Table 3

Run

6000mm

3.1.1

Intermediate landings

0

Table 5

1. Slope

   1 in 12, the steepest Table 3 allows for Accessible ramps.

   3.1.1, Table 3

2. Run

   6000 mm (6 m) of horizontal run for 500 mm of rise at 1 in 12, before landings.

   3.1.1

3. Landings

   None between the ends: 500 mm is within the 750 mm Table 5 allows between landings. Landings at top and bottom still.

   3.3.1, Table 5

1. Sides needing a handrail

   Both sides: an accessible ramp steeper than 1 in 20 takes handrails on both sides.

   6.0.3

D1 only sets the handrail. What fills the side below it is F4/AS1's. Where someone could fall 1 m or more, the side needs a barrier. In housing, or anywhere children under 6 are likely, no gap in it may let a 100 mm sphere through. Elsewhere, gaps may be up to 300 mm between balusters or 460 mm between rails. F4/AS1 Figures 1–4 show barriers a small child can't easily climb. NZBC F4.3.1, F4/AS1 1.2.1, 1.2.2, Figures 1–4

Also under NZS 4121

NZS 4121:2001 is an acceptable solution too, because the Building Act says so at s119, and it sets an accessible ramp of its own. These are the places it asks for something D1/AS1 does not, worked on the ramp above. The D1 and NZS 4121 tab has the whole comparison.

1. Handrail height

   D1/AS1 asks for 900–1000 mm (0.9–1 m) above the pitch line and NZS 4121 asks for 840–900 mm. 900 mm is the only height that meets both, so draw it. Difference 1 on the comparison tab.

   6.0.3, 6.0.6, NZS 4121 6.4.2.6

2. Where the landings fall

   D1/AS1 counts rise, a landing every 750 mm up; NZS 4121 counts run, a landing every 9000 mm (9 m) along. At 1 in 12 this ramp runs 6000 mm (6 m), which is short of both: neither asks for a landing part way up. Difference 3 on the comparison tab.

   Table 5, NZS 4121 6.5.1, NZS 4121 6.5.2

3. Open side of the ramp

   Where a ramp has a drop at its side D1/AS1 asks for a 75 mm upstand. NZS 4121 takes an upstand of 75 mm or an edge rail no higher, and asks for a rail at mid-height between that and the handrail, so a wheel or a stick cannot go over the edge. Difference 6 on the comparison tab.

   3.1.3, NZS 4121 6.4.2.5

4. Everything else

   The steepest slope and the clear width: the same 2 figures in both documents, so a ramp that meets D1/AS1 meets them.

   Table 3, NZS 4121 6.4.2.2, 3.2, NZS 4121 6.4.2.4

What turns

Stairway type

The turn

Pitch line from centre

450mm

Figure 18

Going on the line

232.9mm

4.5.1

Treads in the turn, at most

2

Table 6

1. Stairway type

   Winders on a Main private stairway, which 4.5.1 accepts.

   4.5.1

2. Pitch line

   At the middle of the stairway, which is narrower than 1000 mm (1 m): 450 mm from the centre.

   4.5.2, Figure 18

3. Riser

   180 mm, against a maximum of 190 mm for Main private stairways.

   4.5.1 a), 4.5.1 b), Table 6

4. Tread on the pitch line

   On the pitch line, the going is 232.9 mm, and with the 0 mm nosing the tread is 232.9 mm, short of the 280 mm minimum for Main private stairways.

   4.5.1 a), Table 6, Figure 11

5. Pitch on the pitch line

   On the pitch line, 37.7° is steeper than the 37° maximum for Main private stairways.

   4.5.1 a), Table 6, Figure 11

6. Against the straight flights

   On the pitch line, the going is 232.9 mm, less than the straight flights' 280 mm.

   4.5.1 c), Figure 18

7. How far the winders turn

   90°, no more than 180°.

   4.5.1 e)

8. Treads in the turn

   Every line needs a going of at least 280 mm, which allows no more than 2 treads in this 90° turn, and 3 are drawn.

   4.5.1 a), 4.5.1 c), Table 6

9. Another route

   At this width, BS 585 Part 1 is also an acceptable solution for the winders: it covers stairways 770 to 1200 mm (1.2 m) wide.

   4.5.3

Kind

What this ladder needs

Between landings, at most

6000mm

5.2.1 d)

Safety hoops

Not needed

5.1.2

1. Slope

   65°, within 60° to 70°.

   5.2.1 a)

2. Tread or rung

   120 mm wide, at least 100 mm.

   5.2.1 b)

3. Spacing

   225 mm centres, within 200 to 250 mm.

   5.2.1 b)

4. Width

   500 mm between the stiles, at least 450 mm.

   5.2.1 c)

5. Clearance behind

   100 mm between the treads and any solid object behind, at least 50 mm.

   5.2.1 e) ii)

6. Handrails and openings

   Handrails on both sides, 550 to 750 mm apart, no more than 450 mm above the stile, starting no lower than 900 mm and running 900 mm above the upper landing, with 50 mm for the hand along them; openings at landings of at least 1150 mm (1.15 m).

   5.2.1 e) i), 5.2.1 f), 5.2.1 g)

7. Height between landings

   2700 mm (2.7 m), no more than 6000 mm (6 m).

   5.2.1 d)

8. Safety hoops

   Not needed: the ladder rises no more than 6 m, in one section, and not from a landing or platform.

   5.1.2

9. Spacing

   The same spacing throughout, within ±5 mm.

   5.1.6

Which routes is this door on?

1. Clear opening

   760 mm, against a minimum of 760 mm, which is D1/AS1's accessible door width.

   7.0.3

Also under NZS 4121

NZS 4121:2001 is an acceptable solution too, because the Building Act says so at s119, and it sets doors on an accessible route. These are the places it asks for something D1/AS1 does not. The D1 and NZS 4121 tab has the whole comparison.

1. Force to open

   NZS 4121 caps how hard a door may be to open: 38 N on a hinged door outside, 22 N on one inside, 22 N on a sliding door, fire doors excepted. D1/AS1 sets no force at all, so a self-closer specified to D1/AS1 alone can fail this.

   NZS 4121 7.3.5

2. Vision panel

   D1/AS1 asks for one only where a door swings both ways. NZS 4121 sizes the panel for doors on an accessible route, which can be read as every door on the route. Neither document settles it, so say which reading the drawings took. Difference 10 on the comparison tab.

   7.0.4, Figure 28, NZS 4121 7.3.2 (c), NZS 4121 Figure 21

3. Everything else

   The clear opening, the handle height and the wall beside the handle: the same 3 figures in both documents, so a door that meets D1/AS1 meets them.

   7.0.3, NZS 4121 7.3.1, 7.0.5, NZS 4121 7.3.7 (a), 7.0.1, NZS 4121 7.3.3

1. Height clearance

   2400 mm (2.4 m), against a minimum of 2100 mm (2.1 m) for Pedestrian access routes (unlimited length).

   1.4.1, Table 1, Figure 3

A room of seats

Guest accommodation

What this building needs

Wheelchair spaces

2

8.1.1

Accessible units

2

Table 9

1. Wheelchair spaces

   300 seats need 2 wheelchair spaces; 2 provided.

   8.1.1

2. Under NZS 4121

   NZS 4121, counting 300 people and part of a band, asks for 3, more than the 2 provided.

   NZS 4121 12.2.1.1 (a), NZS 4121 12.2.1.1 (b)

3. Accessible units

   40 guest units need 2 accessible units; 2 provided.

   9.1.1, Table 9

4. Under NZS 4121

   NZS 4121 asks for the same 2, and counts cabins, tent sites and caravan sites as units too.

   NZS 4121 Table 2

5. In each unit

   A 1500 mm (1.5 m) turning circle in the bedroom, sitting and dining areas, a bathroom to G1/AS1, and an accessible kitchen or tea and coffee facilities in line with the other units.

   9.2.1

Table 2 at a glance

Pick a cell to check it below.

• ●Acceptable
• ◐Only if a test shows it
• Not acceptable (blank)

1. Level surfaces including surfaces with slopes no steeper than 1:50.
2. Sloping surfaces with slopes greater than 1:50 but less than 1:10 for wet conditions, or less than 1:8 for dry conditions.
3. Acceptability as shown is based on stair treads without slip resistant nosings. When testing stair treads without nosings acceptability for slip resistance should be on a slope of 1:10. With slip resistant nosings at least 50 mm wide, acceptability criteria for stair treads is based on the requirements for level surfaces.
4. Profile at right angles to direction of pedestrian traffic. Algal growth on uncoated timber walkways significantly reduces slip resistance when wet and requires regular removal, e.g. by high pressure waterblasting.
5. The sand/grit, which is sprinkled over the complete surface of the final paint coating, should be a hard angular material such as silica sand or calcined bauxite. The particle size should not be less than 0.2 mm so that it is not submerged by the coating and not greater than about 2 – 3 mm so that it remains tightly bound to the surface. If overpainted, testing is required to establish acceptability of slip resistance.
6. Concrete surface finishes complying with NZS 3114.
7. Glazed or polished surfaces are unsuitable in either wet or dry conditions for sloping surfaces or for stairs because of the effect of foot placement, even though test measurements may indicate adequacy.
8. The coefficient of friction can vary significantly with the extent of surface preparation.
9. It is noted in AS 4586 that the pendulum slip resistance tests prescribed in that Standard may not be suitable for heavily profiled (or patterned) surfaces.
10. When the grit finish has a “feel” rougher than 80 grit sandpaper, the surface may be deemed to have acceptable wet slip resistance, for either level or sloping surfaces or for stair treads, without testing.
11. Interlocking concrete block paving to NZS 3116.
12. To meet durability requirements of NZBC B2, the surface should have at least a five year life under normal maintenance.
13. Validity of the listed typical values for coefficient of friction is uncertain as the test methods may not be applicable to carpets.
14. Anti-slip tapes will normally require regular replacement to remain effective. To ensure foot contact, tapes should be placed at right angles to the line of travel and be spaced at no more than 150 mm centres.

Check one surface

Condition

Where it is

1. Which columns apply

   1 in 20 is steeper than 1 in 50 and flatter than the 1 in 10 that Note 2 sets for wet conditions, so the sloping surface columns apply.

   Table 2 Note 2

2. Acceptable

   No. Timber, Uncoated smooth does not have acceptable wet slip resistance as a sloping surface.

   Table 2, 2.1.1

Watts per m² in each table

Rows pair the same kind of fitting; where the two tables name it differently, both names are given. Neither table has LEDs.

What to buy

A lamp's box gives lumens (lm) and watts; D1 and G8 ask for lux, which is lumens per m² reaching the treads or the floor. Not all of a lamp's light gets there, so as a rough first pick allow about 2.5 lm from the lamps for every lux you need, per m² of floor:

150 lux for accessible and common stairways: about 375 lm per m², which is roughly 3.8 W of LED per m².

100 lux for private and service stairways: about 250 lm per m², which is roughly 2.5 W of LED per m².

20 lux for the rest of the route, landings and lobbies: about 50 lm per m², which is roughly 0.5 W of LED per m².

For example, the 7 m × 4 m stair lobby both tables are based on is 28 m². At 150 lux it needs about 10500 lm in total: say 14 LED lamps of 800 lm, about 8 W each.

Our rule of thumb, not the documents': about 50% of the light reaches the floor, 80% of that is left once the lamp ages and gets dusty, and an LED gives about 100 lm per watt. Narrow-beam downlights and dark finishes need more; a lighting designer can work it out properly.

Colour temperature isn't set by D1 or G8. Warm white (about 3000 K) is usual in homes and neutral white (about 4000 K) in common areas; either is fine. What matters more on a stair is seeing the edge of each tread: avoid glare, and on an accessible stair make the nosings contrast with the treads (D1/AS1 4.1.7).

Two acceptable solutions, not one on top of the otherBuilding Act 2004 s118, s119, NZS 4121 1.2

NZS 4121 is an acceptable solution because Building Act s119 says so, for the access, parking and toilets s118 asks for in buildings the public uses. Following it is one way to comply, the same as following D1/AS1. NZS 4121 says (1.2) that some of it goes further than the Building Code. That's extra on the NZS route, not something D1/AS1 has to meet as well. Which one your consent authority expects is not something this page can tell you.

Each sends you to the otherNZS 4121 4.5.6, 4.6.1, D1/AS1 10.1.1, 12.0.2

NZS 4121 leaves projections and slip resistance to D1/AS1. D1/AS1 leaves accessible car parks and the lift-by-floor-area test to NZS 4121. So whichever you follow, you end up reading bits of the other.

D1/AS1 12.0.1 points at documents that are goneD1/AS1 12.0.1

To count a floor's occupancy for the lift test, 12.0.1 says to use C/AS2 to C/AS6 or C/VM2. C/AS3 to C/AS6 no longer exist; C/AS2 now covers everything but risk group SH, so that's where the occupant densities are.

NZS 4121 gives two lengths for a kerb rampNZS 4121 1.5.1, 13.4.3.1 (b)

Its definition says a kerb ramp is no longer than 1520 mm (1.52 m); 13.4.3.1 (b) says 1500 mm (1.5 m). Keep it to 1500 mm (1.5 m) and both are met.

NZS 4121 is from 2001NZS 4121 1.4.2, Building Act 2004 s119(4)

It still refers to the Building Act 1991 (s47A). The 2004 Act carries it over in s119, which also says the Minister must recommend adopting a new edition within 6 months of one being published. No new edition has come out.

Stairway type

A private stairway between frequently used spaces: living areas, kitchens, garages. All exterior private stairways are main private. Definitions, pp.14–16

1. Riser height No more than 190 mm for Main private stairways.

   4.1.1, Table 6

2. Tread depth No less than 280 mm for Main private stairways, measured to the front of the nosing.

   4.1.1, Table 6

3. Pitch line slope No steeper than 37° for Main private stairways.

   4.1.1, Table 6, Figure 11

4. Rise between landings No more than 4000 mm (4 m) between successive landings for Main private stairways.

   4.3.2, Table 7

5. Landing size No less than 900 mm long, and no narrower than the access route it serves.

   4.3.3, 4.3.4

6. Line of sight Where landings are more than 8000 mm (8 m) apart vertically, the line of sight between them is broken: offset the flights, turn one by at least 30°, or use a landing at least 1800 mm (1.8 m) long.

   4.3.6

7. Nosings A tread projects no more than 25 mm past a closed riser. With open risers, each tread overlaps the one below by 15–25 mm.

   4.1.6, Figure 12

8. Uniformity Riser height and tread depth are uniform within ±5 mm through each flight, measured at the centreline on straight flights and at the pitch line on curved and spiral flights.

   4.1.3

9. Landings Landings are provided at the top and bottom of every flight, and where a door opens into the stairway.

   4.3.1

10. Landings clear of obstruction Landings are clear of permanent obstruction, with at least 400 mm across the full landing width beyond the arc of any opening door.

    4.3.5, Figure 15

11. A door at a short flight Where the rise of a flight is no more than 600 mm and the door slides or opens away from the steps, no landing is required between the flight and the door.

    4.3.1, Figure 14

12. Pitch line on tapered treads The pitch line of a curved or spiral stairway with tapered treads runs 300 mm in from the handrail on a spiral stairway narrower than 1000 mm (1 m), and 300 mm in from each side on a curved stairway 1000 mm (1 m) wide or more.

    4.4.1, Figure 17

    N/A
13. Tapered treads Consecutive tapered treads have a uniform taper angle, and the pitch line slope, riser height and tread depth along both pitch lines meet Table 6 and Figure 11.

    4.4.2, Table 6, Figure 11

14. Narrow spiral stairways A spiral stairway narrower than 1000 mm (1 m) serves only as a private or service stairway.

    4.4.1 a), Figure 17(a)

15. Winders Winders only on private and service stairways, and only where the riser and tread on the pitch line meet Table 6 and Figure 11, the riser is uniform and the same as on the straight flights either side, the tread on the pitch line is no less than on those flights, the winders have a uniform taper angle, and consecutive winders turn through no more than 180°.

    4.5.1, Table 6, Figure 11

    N/A
16. Pitch line on winders The pitch line at the middle of a stairway narrower than 1000 mm (1 m), and 300 mm in from each side of one 1000 mm (1 m) wide or more.

    4.5.2, Figure 18, Figure 17(b)

Type of ramp

On an accessible route. Carries the upstand and clear width requirements of 3.1.3 and 3.2.

1. Slope No steeper than 1 in 12 for Accessible ramps.

   3.1.1, Table 3

2. Rise between landings For a ramp steeper than 1 in 33, intermediate landings at no more than 750 mm of rise.

   3.3.1, Table 5

3. Landing length No less than 1200 mm (1.2 m).

   3.3.3, Table 5

4. Upstand No less than 75 mm on any drop-off side of the ramp.

   3.1.3, Figure 9

5. Clear width The clear width of an accessible ramp is 1200 mm (1.2 m).

   3.2

6. Ramp landings Ramp landings are level and clear, and landing width is no less than the minimum width of the ramp they serve.

   3.3.2, 3.3.3

7. Ramp surface The ramp surface is a slip resistant surface complying with Table 2.

   3.1.4, Table 2

1. Where a rung-type ladder does not go No rung-type ladder where access is frequent and tools, equipment or materials are carried.

   5.1.1

2. Nobody underneath A fixed ladder within an access route placed so that nobody working or walking beneath it is endangered while it is climbed.

   5.1.3

3. Ladder landings Landings no narrower than the ladder they serve, and as long as it is wide, or longer where 5.1.7 asks.

   5.1.4, 5.1.5

4. Even spacing Rungs or treads spaced uniformly within ±5 mm through the whole ladder installation.

   5.1.6

5. Safety hoops Protection from falling from a ladder that rises more than 6 m above the ground or rises from a landing or platform: safety hoops and longitudinal straps of 50 × 8 mm grade 250 steel, the hoops no more than 1000 mm (1 m) apart, the highest level with the top of the barrier on the platform reached and the lowest 2.5 m above the ground or platform.

   5.1.2

6. Hoop dimensions Hoops dimensioned as Figure 21: rectangular, 700 to 750 mm across and deep, with corners of at least 150 mm radius; or circular, of 350 to 400 mm radius and 750 to 850 mm deep, with at least 400 mm open at the ladder.

   5.1.2 b), Figure 21

7. Arresting a fall An installation of more than one ladder section, more than 6 m high in all, has as well as its hoops a change of direction between successive ladders at each landing, successive ladders offset at each landing, or landings at least 1.5 m long.

   5.1.7, 5.1.5

   N/A
8. Step-type ladders A slope of 60° to 70° from the horizontal; treads at least 100 mm wide, evenly spaced at 200 to 250 mm centres; at least 450 mm between the stiles; and no more than 6 m between landings.

   5.2.1, Figure 19

   N/A
9. Step-type clearances At least 50 mm for the hand along the handrail and 50 mm between the treads and any solid object behind the ladder, and horizontal openings at landings of at least 1150 mm (1.15 m).

   5.2.1 e), 5.2.1 f)

10. Step-type handrails Handrails on both sides, 550 to 750 mm apart, no more than 450 mm above the stile, starting no lower than 900 mm above the floor, running at least 900 mm above the upper landing to meet any barrier, and built to 6.0.1 to 6.0.6.

    5.2.1 g)

11. Rung-type ladders A pitch line slope of 70° to 90° from the horizontal; rungs at least 20 mm in diameter, evenly spaced at 250 to 300 mm centres; 350 to 500 mm between the stiles; and no more than 9 m between landings.

    5.3.1, Figure 20

    N/A
12. Rung-type clearances At least 750 mm between the rungs and any obstruction behind the climber, 300 mm from the ladder's centre line to each side, 50 mm for the hand along stiles that run above a landing, and 200 mm between the rungs and any solid object behind the ladder.

    5.3.1 e)

13. Getting off a rung-type ladder Stiles running to the height of the barrier and at least 900 mm above the landing, and no toeboard across the ladder opening. For step-through access, stiles 500 to 700 mm apart above the landing and the top rung level with it or one full rise below; for side access, 150 to 300 mm from the nearest stile to the landing and the top rung level with it.

    5.3.2, Figure 22, Figure 23

14. Individual rungs Rungs at least 25 mm in diameter, shaped so a foot cannot slip off sideways, evenly spaced at 250 to 350 mm centres; a tread on each rung 300 to 550 mm wide, or at least 200 mm where the rungs are staggered; and a rung-type ladder's height of no more than 9 m between landings, and its clearances.

    5.4.1, Figure 24

    N/A

1. Height Between 900 mm and 1 m above the pitch line, measured to the top of the handrail.

   6.0.6, Figure 25

2. Slope and length The same slope as the pitch line, beginning no further than the second riser from the lower end, and extending the full length of the stairway it serves.

   6.0.4

3. Under the handrail D1 only sets the handrail. What fills the side below it is F4/AS1's. Where someone could fall 1 m or more, the side needs a barrier. In housing, or anywhere children under 6 are likely, no gap in it may let a 100 mm sphere through, and the triangle between the tread, riser and bottom rail must not let a 150 mm sphere through. Elsewhere, gaps may be up to 300 mm between balusters or 460 mm between rails. F4/AS1 Figures 1–4 show barriers a small child can't easily climb. On Stairways.

   NZBC F4.3.1, F4/AS1 1.2.1, 1.2.2, Figures 1–4

4. Extensions A horizontal extension of at least 300 mm at each end. Extensions may be turned down rather than ended abruptly, and the first riser sits far enough back from the corner to accommodate one. On Ramps.

   6.0.4, Figures 9 and 25

5. Under the handrail D1 only sets the handrail. What fills the side below it is F4/AS1's. Where someone could fall 1 m or more, the side needs a barrier. In housing, or anywhere children under 6 are likely, no gap in it may let a 100 mm sphere through. Elsewhere, gaps may be up to 300 mm between balusters or 460 mm between rails. F4/AS1 Figures 1–4 show barriers a small child can't easily climb. On Ramps.

   NZBC F4.3.1, F4/AS1 1.2.1, 1.2.2, Figures 1–4

6. Handrail profile Handrail profiles can be readily grasped by an adult hand.

   6.0

1. Barrier on the stair No less than 900 mm, measured vertically from the pitch line or the nosings. F4/AS1 Table 1, Detached dwellings and within household units of multi-unit dwellings: Stairs and ramps and their intermediate landings. On Stairways.

   F4/AS1 Table 1, F4/AS1 Table 1 Note 1

2. Barrier at the floor edge No less than 1000 mm (1 m) where the stair meets a floor edge, measured from finished floor level. F4/AS1 Table 1, Detached dwellings and within household units of multi-unit dwellings: Balconies and decks, and edges of internal floors or mezzanine floors.

   F4/AS1 Table 1, F4/AS1 Table 1 Note 1

3. Handrail on the barrier Where a handrail is mounted on top of a stairway barrier, it may transition up to 1100 mm (1.1 m) on the intermediate landings. On Stairways.

   F4/AS1 Table 1 Note 5

4. Barrier on the ramp No less than 900 mm, measured vertically from finished floor level. F4/AS1 Table 1, Detached dwellings and within household units of multi-unit dwellings: Stairs and ramps and their intermediate landings. On Ramps.

   F4/AS1 Table 1, F4/AS1 Table 1 Note 1

1. The route An accessible route is continuous, can be negotiated unaided by a wheelchair user, and runs from the street boundary or car parking area to the spaces within the building required to be accessible.

   Definitions, Accessible route

2. Clear width No less than 1200 mm (1.2 m) along an accessible route.

   2.2.1

3. Edge of an accessible route Where an accessible route is more than 25 mm above the adjacent ground, a 75 mm upstand or a low barrier rail is provided.

   2.3.1

   N/A
4. Kerb ramps Kerb ramps have a slope no greater than 1 in 8, and colour and texture contrast with the adjacent footpath.

   3.4.1

   N/A

Risk group, for the escape route figures

Escape route figures are C/AS1's for risk group SH and C/AS2's for every other group. Set the classified use on the project, or pick the group here.

1. Clear opening Accessible doors have a clear opening of at least 760 mm.

   7.0.3

2. Swing and height Opens no less than 90°, and the opening has a clear height of no less than 1955 mm (1.955 m) for the required width. The door swing must not obstruct the minimum required width of the escape route.

   C/AS1 3.2.4.1 b), C/AS1 3.2.4.1 c), C/AS2 3.9.4.5(a), C/AS2 3.9.4.5(c), C/AS1 3.2.1 b), C/AS2 3.2.1.1(b)

   N/A
3. Space beside the handle Where a person must open the door towards the wheelchair, an unobstructed wall space of no less than 300 mm at the handle side.

   7.0.1, Figure 27 (b)

4. Handle height Between 900 mm and 1200 mm (1.2 m) above floor level, lever action, openable with one hand, with the handle end returned towards the door.

   7.0.5

5. Contrast Accessible doors are of a colour that contrasts with their surroundings.

   7.0.4

6. Doors swinging both ways Doors that swing in both directions incorporate glazing that gives a person using the door adequate visibility, as Figure 28 shows.

   7.0.4, Figure 28

   N/A
7. Revolving doors and turnstiles Where revolving doors or turnstiles are used within an accessible route, an alternative hinged or sliding door is provided.

   7.0.6, Figure 29

   N/A
8. Frameless glass doors Frameless glass doors comply with NZBC F2.

   7.0.7, NZBC F2

   N/A

1. Wheelchair spaces 2 spaces for wheelchairs where there are up to 250 seats, and 1 more for every additional 250 seats.

   8.1.1

2. Where they are The wheelchair spaces immediately next to other seating, as Figure 30 shows.

   8.1.2, Figure 30

3. The stage An accessible route to the podium or stage.

   8.2.1

   N/A

1. How many Accessible accommodation units in hotels, motels and other Communal Residential buildings that house the public, at least as Table 9 gives: 1 for up to 10 guest units, 2 for up to 25, and 1 more for every additional 25.

   9.1.1, Table 9

2. What each one has Toilet and bathroom facilities that comply with G1/AS1; bedrooms, sitting and dining areas with clear floor for a 1500 mm (1.5 m) turning circle; and an accessible kitchen or accessible tea and coffee making facilities, in line with what the building's other units have.

   9.2.1

Risk group, for the escape route figures

Escape route figures are C/AS1's for risk group SH and C/AS2's for every other group. Set the classified use on the project, or pick the group here.

1. D1 on an escape route Ramps, stairs, ladders, landings, handrails, doors, vision panels and openings on an escape route meet D1/AS1.

   C/AS1 3.1.1.1, C/AS2 3.1.1.6

2. Stairs and ladders in an open path, C/AS1 A stair in an open path counts as its plan length measured on the stair's centreline plus the plan length of each landing, and a ladder as its vertical height.

   C/AS1 3.3.2.1 c), C/AS1 3.3.2.1 d)

3. Stairs and ladders in an open path, C/AS2 A straight or curved stair in an open path counts as its plan length on the centreline times 1.2, plus the plan length of each landing; a spiral stair as 2 times its vertical height; and a ladder as 3 times its vertical height.

   C/AS2 3.3.4.1

4. Handrails in the width A handrail that meets D1/AS1 may project no more than 100 mm into the width of an escape route.

   C/AS1 3.2.3.1 a), C/AS2 3.2.4.1(b)

5. Curved and spiral stairs A curved or spiral stair on an escape route has its required width measured across the treads where their depth meets D1/AS1's tread depth.

   C/AS2 3.2.3.3

6. Ladders as escape routes A ladder as an escape route only from a dead end, for risk groups other than SM and SI, where it serves only support activities and the occupant load does not normally exceed 4. Nowhere else.

   C/AS2 3.4.10.3, C/AS2 3.4.10.4

1. Height clearance Height clearances along every access route comply with Table 1, as Figure 3 shows them.

   1.4.1, Table 1, Figure 3

2. Minor projections A minor projection is only permitted at all if it is designed to minimise the risk of injury or impact.

   1.5.1

1. Walking surfaces Slip resistance by 2.1.2 to 2.1.5: a surface Table 2 accepts for the situation, or the AS 4586 test method those paragraphs name.

   2.1.2, 2.1.3, 2.1.5, Table 2

2. Wet to dry transition The transition zone between the part of an access route intended to remain dry and the part that may become wet is provided with absorbent matting, an extension of the wet slip resistant surface, or both.

   2.1.6

   N/A

1. Light at the treads At least 100 lux at tread level for private and service stairways.

   4.6.1, Table 8 Notes

2. Light on the route At least 20 lux at floor level along the access route, landings and lobbies included.

   NZBC G8.2 b), G8.3, G8/VM1

3. Switches Except on external private stairways, stairway lighting switches can be activated at the top, at the bottom, and at any intermediate landing having access to or from a floor.

   4.6.2

   N/A

Stairway: Main private. Ramp: Accessible. Escape routes: risk group not given.

Service (stairway)Definitions, pp.14–16

Used infrequently by service personnel to reach spaces for maintenance and the movement of goods.

Minor private (stairway)Definitions, pp.14–16

A private stairway off the main thoroughfare, giving infrequent access to a single room that is not a living area.

Secondary private (stairway)Definitions, pp.14–16

A private stairway that is neither main nor minor, reaching a floor containing only bedrooms, a bathroom or similar.

Main private (stairway)Definitions, pp.14–16

A private stairway between frequently used spaces: living areas, kitchens, garages. All exterior private stairways are main private.

Common (stairway)Definitions, pp.14–16

Used by the public, whether as of right or not, and not private, service or accessible.

Accessible (stairway)Definitions, pp.14–16

On an accessible route: a route a person with disabilities can negotiate, extending from the street boundary or car park to the spaces required to be accessible.

Accessible (ramp)Table 3, 3.1.1

On an accessible route. Carries the upstand and clear width requirements of 3.1.3 and 3.2.

Common, subject to wetting (ramp)Table 3, 3.1.1

A ramp used by the public that can get wet: external, or otherwise exposed.

Common, normally dry (ramp)Table 3, 3.1.1

A ramp used by the public that stays dry in normal use.

Service (ramp)Table 3, 3.1.1

Used infrequently by service personnel for maintenance and the movement of goods. Steep enough to need footholds beyond 1 in 8.

Pitch lineDefinitions p.15, 4.1.1

The line joining the nosings of successive treads. Its slope, riser over tread on a uniform flight, is what Table 6 limits and what a handrail follows.

Accessible routeDefinitions, pp.14–16, 2.0

A route a person with disabilities can negotiate, extending from the street boundary or car park to the spaces required to be accessible. Doors, ramps and stairways on it carry the accessible requirements.

Table 6 and Table 7 do not share a list of stairwaysTable 6, Table 7, Definitions, pp.14–16

Table 6 splits private stairways into main, secondary and minor; Table 7 does not. All three are defined as private stairways (Definitions, pp.14–16), which is how they are mapped to Table 7's Private row here. Neither table states it.

The gait comment under 4.1.14.1.1 COMMENT, Figure 2

Below 23° a stair does not allow an acceptable gait, and broken rhythm is where dangerous falls happen. A comment on 4.1.1, not a requirement: noted beside a design, never counted against it.

D1 and G8 price the same room differentlyTable 8 Notes, G8/AS1 Table 1 Note 4, G8/VM1 1.0.3

D1/AS1 Table 8 and G8/AS1 Table 1 both work from the same room: a 7 m × 4 m stair lobby. G8 wants 20 lux on the floor; D1 wants 100 lux (private and service stairs) or 150 lux (accessible and common) at the treads. Divide the light by the watts and they don't agree: for the same kind of fitting, D1 gets 2.4 to 3.8 times as much light from each watt as G8 does. Neither document says why. Our guess: G8's 20 lux is the dimmest spot on the floor (G8/VM1 measures the low points), while D1's reads like an average. Either way, don't scale one table to get the other. Use G8 for the lobby and D1 for the treads.

Spiral stairways1.4.1 COMMENT

1.4.1's COMMENT: take particular care over the height clearance between the pitch line and the underside of an upper tread where spiral stairways are used. The clearance itself is Table 1's.

An accessible curved stairwayFigure 17(b)

Figure 17(b) accepts a curved stairway 1000 mm (1 m) wide or more as an accessible stairway where it has handrails on both sides.

Another route for spiral stairways4.4.1, 4.4.1 COMMENT 2

BS 5395 Part 2 is an acceptable solution for a spiral stairway no less than 1500 mm (1.5 m) in diameter. The COMMENT adds that a smaller one built to it may serve as an additional way to a space that other access routes already serve well.

Why the lines are where they are4.4.1 COMMENT 1

The COMMENT explains Figure 17: people are taken to walk up and down only on the outside of a narrow stairway, and on both the inside and the outside of a wider one.

Another route for winders4.5.3

BS 585 Part 1 is an acceptable solution for winders on stairways 770 to 1200 mm (1.2 m) wide.

Most risers, by slope1.2.1, Figure 2, Table 6

Up to 30 risers before this stops being a stairway: Figure 2 draws the line between a ramp and a stair at 18°, and at 30 risers with the 280 mm minimum tread the pitch is 18.16°. Beyond that no tread brings it back above 18°.

Width4.2.1 COMMENT

D1/AS1 sets no minimum width for a stairway within a household unit. Its comment points at C/AS2 3.3.2's 850 mm for risk group SM as a practical minimum for any private stairway, and notes that narrower stairs make moving furniture difficult.

A figure, not a minimum3.2, 2.2.1

3.2 states the clear width of an accessible ramp as 1200 mm (1.2 m), not as a minimum, where 2.2.1 words an accessible route's as no less than 1200 mm (1.2 m). A ramp on an accessible route is part of that route.

Glazed and polished ramps3.1.4 COMMENT 2

3.1.4's COMMENT: glazed or polished walking surfaces are normally unsuitable for common ramps (see Table 2's notes).

Choosing a ladder5.1.1 COMMENT 1

The COMMENT asks for thought about why access is needed, how often, and whether tools or materials are carried by hand. It says a rung-type ladder does not suit the way to a lift machine room or plant room visited at least monthly with tools or materials, and does suit roofs, pits, silos, towers, chimneys and tanks reached infrequently.

Ladders in Housing5.1.1 COMMENT 2, 5.1.1

The COMMENT accepts ladders in Housing to reach spaces used infrequently, such as attics and lofts. BS EN 14975 is an acceptable solution for retractable loft and attic ladders in housing, and for maintenance access in other buildings.

The barrier Figure 20 drawsFigure 20, 11.0.1 COMMENT, F4/AS1 Table 1

Figure 20 draws the barrier at the top of a rung-type ladder 1000 mm (1 m) high. 11.0.1's COMMENT says a barrier of that height is to be treated as an alternative solution to F4/AS1 Table 1, whose height for places outside housing is 1100 mm (1.1 m). So a barrier built to the drawing's height is an alternative solution, not D1/AS1's.

Another route for service access11.0.1

AS 1657 is an acceptable solution for the stairs, ladders, platforms and walkways that service and maintenance people use.

Two units for one range6.0.6

6.0.6 writes the lower bound as 900 mm and the upper as 1 m: one range in two units, 900 to 1000 mm (1 m).

Counting by people8.1.1, NZS 4121 12.2.1.1

NZS 4121 counts the people a room holds, standing room included, and adds a space for part of a band as well as a whole one, so between whole bands it asks for one more. Seats and rooms works both counts for one room.

Kitchens9.2.1 COMMENT

The COMMENT points to MBIE's guidance on accessible units in public accommodation. The G3 page works an accessible kitchen, NZS 4121's figures included.

Car parks10.1.1, 10.1.1 COMMENT

AS/NZS 2890 Part 1 is an acceptable solution for car parks and the routes through them. The COMMENT sends accessible parking, and how many parks there are to be, to NZS 4121 Section 5, which the NZS 4121 page works.

Loading spaces11.0.2, References

11.0.2 names AS 2980 Part 2 as an acceptable solution for loading spaces and routes for commercial vehicles. The document's References list gives AS/NZS 2890 Part 2, off-street commercial vehicle facilities, for 11.0.2, so the number in the paragraph reads as a slip. Neither standard is held here.

Durability of the surfaceTable 2 Note 12, NZBC B2

Table 2's Note 12: to meet NZBC B2, a walking surface should have at least a 5 year life under normal maintenance. A should in a table note, so it is read here rather than listed; the requirement itself is B2's, and B2's periods are on the B2 page.