Zoning review before design, not after.
The expensive way to design an addition is to draw the one you want and then find out what you are allowed to build. We do it in the other order.
$220k-$520kChicago range
€1,400-2,300/m²Lisboa range
20-30 wkOn site
$2,400Survey, before any of it
Service 04 of 07. Priced from your survey, never from an average.
Why this is one job and not several
Because setback, lot coverage, height and, in Lisboa, the municipal plan and any historic overlay decide the envelope before taste gets a vote. Drawings made inside the real envelope get permitted; drawings made outside it get redrawn at your cost.
What is included
- Zoning and planning review before design
- Engineering, permit drawings and submission management
- Foundations, structure, envelope and roofing
- Full internal fit-out to the agreed specification
- Making good to the existing building at the junction
What is not
- Landscape beyond 1.5m of the new wall
- Utility upgrade charges levied by the provider
- Party wall awards where a neighbour appoints their own surveyor
- Fixtures above the stated allowance
The junction is the engineering
How the new roof meets the old one, and whether the existing wall can carry it, is settled by an engineer at survey stage rather than argued about on site.
Four things move this number more than any finish you will choose.
What decides the price
01
Zoning envelope
Setbacks, lot coverage and floor area ratio in Chicago; the PDM and any historic overlay in Lisboa. Established in week one, in writing.
02
Foundation type
Soil, frost depth and the existing footing decide whether you are on strip footings, piles or a raft. It is the largest single cost variable in an addition.
03
Structural connection
How the new roof meets the old one, and whether the existing wall can carry it, is engineering rather than opinion. An engineer sees it at survey stage.
04
Utility relocation
A meter, a stack or a service head inside the footprint is a schedule item measured in weeks, because the utility sets the date, not us.
One we finished, three weeks late and published.
A recent one, in full
A rear addition on a 1924 bungalow. The first sketch was 600mm too deep for the lot coverage, which we established on paper in week one rather than at permit in month three. The sill plate under the rear wall was soft for 2.4m and had to be replaced before anything could sit on it. The ridge beam then arrived 90mm short and cost three weeks, which we published to the owners the day the fabricator told us.
Read the Oak Park Bungalow file — $312,750 · 26 weeks · three weeks late · 2024.
Four things, starting with your plat of survey.
What we need from you first
01
Your plat of survey, or the equivalent
Setback, lot coverage and easements are the envelope. Everything we draw has to live inside it, so we read it before we draw.
02
What the addition is actually for
"More space" prices differently from "a kitchen that opens onto the garden". The second one tells us where the services have to go.
03
Whether you have spoken to a neighbour
In a party-wall or a tight-lot situation, one conversation in week one saves a month later.
04
Your tolerance for the permit calendar
We give you the authority's current median, not our hopes. If that date does not work, there are usually two scopes that avoid the review entirely.
The envelope first, the drawing second.
We establish what your lot and your authority will allow in writing before anyone draws inside it. That review is week one of the survey, not a hope held later.