Programme template

Double-storey extension: typically 16–22 weeks.

Two-storey side or rear extension with new bedroom over kitchen/living space, tied into the existing roof.

Durations are typical ranges for a well-run job with normal lead times — actual programmes vary with site conditions, weather and procurement.

Stage-by-stage

Site set-up & demolition4–6 days
◆ BC: commencement noticeinspection / milestone
Excavation & footings6–10 days
◆ BC: excavation inspectioninspection / milestone
Foundations & ground floor slab6–9 days
◆ BC: DPC & drains inspectioninspection / milestone
Masonry to first floor8–12 days
First floor joists & deck3–5 days
Masonry to wallplate8–12 days
Steels & structural openings3–5 days
Roof structure, tie-in & coveringExisting-roof tie-in is the weather-critical stage8–12 days
Watertight: windows & doors3–5 days
First fix (electrics, plumbing, carpentry)8–12 days
Plastering6–9 days
Plaster drying5–10 days
Second fix & bathroom/kitchen install10–15 days
Decoration & flooring6–10 days
Snagging & clean3–5 days
◆ BC: completion inspectioninspection / milestone

Customise this programme:

Residential

Commercial

Packages

Start date

Typical durations for a well-run job — actual programmes vary with site, weather and lead times.

Adjust stage durations

Site set-up & demolition4d (4–6)Excavation & footings6d (6–10)Foundations & ground floor slab6d (6–9)Masonry to first floor8d (8–12)First floor joists & deck3d (3–5)Masonry to wallplate8d (8–12)Steels & structural openings3d (3–5)Roof structure, tie-in & covering8d (8–12)Watertight: windows & doors3d (3–5)First fix (electrics, plumbing, carpentry)8d (8–12)Plastering6d (6–9)Plaster drying5d (5–10)Second fix & bathroom/kitchen install10d (10–15)Decoration & flooring6d (6–10)Snagging & clean3d (3–5)

Completed In Progress Upcoming

27 Jul17 Aug8 Sept30 Sept22 Oct

Site set-up & demolition

BC: commencement notice

Excavation & footings

BC: excavation inspection

Foundations & ground floor slab

BC: DPC & drains inspection

Masonry to first floor

First floor joists & deck

Masonry to wallplate

Steels & structural openings

Roof structure, tie-in & covering

Watertight: windows & doors

First fix (electrics, plumbing, carpentry)

Plastering

Plaster drying

Second fix & bathroom/kitchen install

Decoration & flooring

Snagging & clean

BC: completion inspection

Turn this into a live tracked project — weekly updates, photos and RAG status your client can follow. Track this build live — free

Single-storey rear extension →Loft conversion (dormer) →Wraparound extension →Full house refurbishment →New-build house (single plot) →Small residential development (2–6 plots) →