Proxicost / Residential cost engine / UK

Stop clients designing projects they cannot afford.

Proxicost gives architects a credible UK residential build cost at RIBA Stages 1 to 2, line by line and in minutes. Shape scope and client expectations before a quantity surveyor is engaged.

Worked example01 / 05

Rear extension

32 m² · Zone 2-6

£0
£100k
£200k
Basic
£68,000
Mid
£86,000
Premium
£115,000

One project, specced basic to premium · budget, not a quote

Fig. 02/Live ballpark

See a real number in three answers.

Project
Size

Priced from 5 to 150 m² for an extension

Location

Grand total by spec level

Calculating

£0
£100k
£200k
Basic
£106,000
Mid
£133,000
Premium
£180,000

The three figures are the same project specced basic, mid or premium throughout. In the full estimate you choose the spec item by item. Budget range, not a quote.

Fig. 03/How we know

Rates from real London projects. Adjusted for the realities of yours.

01 / Experience
0

Years of residential construction pricing experience

02 / Current
Live rates

Material prices kept current with the market, not a static annual book

03 / Coverage
0

Extensions, refurbishments, lofts, basements and one-off homes

Proxicost is built and priced by the team behind a London architecture-led practice with 17 years pricing the residential work it builds. Rates are kept current as material and labour costs move, so your number reflects today’s market rather than last year’s price book. Every estimate is then adjusted for your London zone, listed or conservation status, and access difficulty.

Fig. 04/Where Proxicost fits

A feasibility number before you bring in a QS.

Proxicost is the conversation you have in week one, not the document you commission in week six. It is built for generic-spec residential schemes. Highly bespoke schemes, where cost is driven by detail a questionnaire cannot capture, warrant a quantity surveyor, and Proxicost does not try to replace one.

Comparison
Proxicost
Traditional QS
Cost
Free during beta
£500 to £1,500
Time
Minutes
2 to 4 weeks
Output
Line-by-line budget at the spec you choose
Itemised tender quote