▙ JengaCost

Design studio

Get a preliminary house concept in seconds — a to-scale floor plan, door & window schedules, a build programme and a fully priced draft BOQ from Kenyan county-adjusted rates.

Concepts are for budgeting only — approvals-ready drawings come from a registered professional.

✨ New: just describe your project
"3 bedroom bungalow with a master ensuite…" — the AI designs it and drafts the whole BOQ for you.
Describe it →

Real plans with a fixed layout. Each one opens in the cost explorer with its drawings, 3D view and a priced bill.

Civil works — roads & drainage
for contractors & counties

Tender-ready starter bills priced from the public roads schedule of rates, adjusted to your county. Open one to see its typical drawing and every quantity before you create it.

County / national tender
Typical drawing: Murram access road — 1 km
Murram access road — 1 km
6m carriageway: clearing, formation, 150mm gravel wearing course, side drains and three culvert crossings.
Typical drawing: Culvert crossing — 900mm pipes
Culvert crossing — 900mm pipes
Single stream crossing: excavation, twin 900mm pipes, masonry headwalls, pitching and gabion protection.
Typical drawing: Roadside drainage, both sides — 1 km
Roadside drainage, both sides — 1 km
Open lined side drains to a 1 km rural road: 2 km of drain excavated to profile, grouted stone pitching, scour checks, six culvert crossings and gabion outfalls.
Typical drawing: Piped storm water drainage — 500 m
Piped storm water drainage — 500 m
Urban storm drain under a carriageway or footway: trench, 600mm pipeline, concrete surround, manholes and road gullies, discharging to a protected outfall.
yours to price 5 lines measured in full and left at nil — see which.
Typical drawing: Footway & kerbing, both sides — 1 km
Footway & kerbing, both sides — 1 km
2m paved walkway each side of a 1 km road: base, cabro, precast kerbs to both faces, gullies at the channel and marked crossings.
yours to price 1 line measured in full and left at nil — see which.
Private / developer
Typical drawing: Plot drainage & erosion control
Plot drainage & erosion control
Cut-off drains, grouted stone pitching, gabions and grassing for a typical residential plot on a slope.

Items the library has no rate for — manholes, catchpits, small-bore pipes, trench support, and the contractor's own obligations in Bills 1 and 9 — are measured in full and left at nil for you to price. On a tender you are issuing that is the correct form: the rate column is the question. On one you are pricing, those are the lines to put your own build-up against first.

External works — a plot with no building on it
compound & forecourt

The wall, the gate, the drive, the septic tank and the water storage, costed on their own. The job that gets left out of the house budget.

Site plan: Compound external works, quarter acre
Compound external works, quarter acre
Perimeter wall and gate, cabro drive and parking, paths, septic and soakpit, water storage and garden on a quarter acre — the job that gets left out of the house budget.
Sign up free to create
Site plan: Paved forecourt & perimeter, eighth acre
Paved forecourt & perimeter, eighth acre
A hard-standing yard behind a walled frontage — cabro throughout, a wide gate for a lorry, and a small planted strip. The commercial plot before anything is built on it.
Sign up free to create
Or size one to a room list: