Zero-Threshold Feasibility Checker
Enter the level change (mm), the door location and whether drainage is available — and get a verdict: flush OK, bevelled saddle, channel-drain + slope, or a ramp. Checked against the RPwD ≤12 mm accessible rule. Indicative India 2026 guidance.
Your threshold
Height difference between the two floor finishes at the door (measure across the opening, worst point).
Dry internal door. Easiest case for a flush / zero threshold — no rain to manage. Flush limit 6mm (square upstand); above that it must be bevelled. RPwD accessible limit 12mm; above that you need a ramp / regraded floor.
Measured level change
0 mm
vs flush ≤6mm · accessible ≤12mm (RPwD)
Flush threshold OK
A 5mm change is within the 6mm flush limit and the 12mm accessible limit. A true zero / level threshold is feasible.
Accessible?
Within ≤12mm
Flush possible?
Yes (≤6mm)
What to build
Run the floor finish through level with a flush saddle (stone/timber/aluminium strip). No ramp or drain needed here — this is the gold-standard barrier-free detail.
Free egress (RPwD / NBC): a flush, level threshold is the gold standard for step-free escape and wheelchair access — never let a saddle, drain grate or weather-bar create a lip that blocks an exit route.
Your level change vs the limits
The flush limit is 6mm (square upstand) and the RPwD accessible limit is 12mm (bevelled above 6mm). Your bar stays green while it is feasible.
Dashed lines mark the 6mm flush and 12mm accessible thresholds. Indicative — confirm on site.
Detail a step-free, dry threshold
DesignAI helps you build the threshold detail — saddle, drainage, slope and waterproofing — so it stays accessible and never leaks.
Assumptions & notes
- Limits follow the RPwD Act / Harmonised Guidelines for accessible built environments: a level threshold is ideally flush, may be a square upstand up to 6mm, must be bevelled (chamfered) from 6–12mm, and needs a ramp / regraded floor above 12mm.
- Wet and external doors need a channel / linear drain with a 1:80–1:60 fall away from the door, plus continuous waterproofing under and beyond the saddle. External thresholds also need DPC and an anti-termite course at the frame base in India.
- Free egress (RPwD / NBC): keep escape routes step-free — saddles, grates and weather-bars must not create a tripping lip on an exit.
- This is a guidance tool, not a substitute for a skilled carpenter, plumber or site engineer. Indicative — confirm with your carpenter / fitter on site, and measure twice. No costs are estimated here; where threshold, drain and finishing work is quoted, 18% GST applies on materials and labour in India.
Related Guides — Deep-dive reading
Zero Threshold Doors in India: Level Access (India 2026)
How to detail a flush, step-free door threshold for wheelchairs and ageing-in-place while still keeping monsoon water out.
Home Doors & EntrancesDoor Threshold Types Compared: Which to Use (India 2026)
Stone saddle, ramped, recessed, aluminium seal strip or weather-bar threshold — which type suits internal, external, wet and wheelchair-accessible doors, and what each costs.
Home Doors & EntrancesWheelchair Accessible Doors for Indian Homes: Clear Width, Thresholds & Hardware (2026)
The exact specs that make a door usable from a wheelchair - clear opening width, near-flush threshold, lever hardware, approach clearance and low-force or auto operation, mapped to the RPwD Harmonised Guidelines 2021.
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