40 Wrottesley Road: Extension & Loft Conversion
40 Wrottesley Road, Brent, London NW10 5YG
Side and rear extensions with a hip-to-gable loft conversion for a corner house in Brent. ACDS provided planning, Building Regulation drawings and structural design; construction is underway.
Project overview
The Project
At 40 Wrottesley Road, the brief combines a two-storey side and rear extension, a deeper single-storey rear addition and a hip-to-gable loft conversion with a rear dormer. The semi-detached house occupies the corner of Wrottesley Road and Odessa Road in Brent.
The challenge
The side extension’s flank wall and roof face Odessa Road, making them part of the street scene. At the rear, the additions sit beside No. 42. The design needed to address both relationships, with different depths and roof heights for the ground-floor and two-storey elements.
Our role
Appointed in 2026, ACDS provided planning and Building Regulations work alongside structural drawings and calculations. Our house extension drawings brought the replacement of the side garage, rear additions and roof conversion into one scheme.
Project stage: planning approved and under construction. Site photographs show installed steelwork, new masonry, timber roof framing and the rear dormer taking shape.
Drawings and project imagery
Project Gallery
10 presentation plates
Selected architectural drawings, technical details and project views from the coordinated design package.
Swipe to view drawings
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Planning strategy
Planning & Heritage
Why the rear extensions have different depths
At first-floor level, the side extension steps back 500 mm from the original front wall. That setback keeps the original frontage legible, while the new ridge and eaves remain within the height of the existing house.
The two-storey rear extension stops 3 metres beyond the original rear wall. Our drawings showed the nearest habitable-room window at No. 42 and the 45-degree line used to assess the neighbour’s relationship with the addition. Brent’s officer accepted that arrangement.
The ground-floor extension continues another 3 metres, giving a total depth of 6 metres. Beside No. 42, its pitched roof has an eaves height of 2.45 metres. This meets a flat-roof portion no higher than 3 metres above ground level. The extra depth is therefore kept at ground-floor level, with a low edge towards the adjoining property.
No. 42 already has a rear extension. The officer assessed the proposed ground-floor addition as projecting 3 metres beyond that existing extension and found the effect on outlook and daylight acceptable. That existing arrangement mattered to the assessment; the 6-metre depth alone does not explain the planning outcome.
Spatial design
Architectural Design
Making the gable and dormer work with the side extension
Changing the original hip to a gable affects the whole side elevation. With a two-storey side extension below it, the loft conversion needed to be considered as part of the enlarged house’s roof composition.
The planning case addressed the surrounding roof forms. During the site visit, Brent’s officer noted hip-to-gable conversions at other properties on Wrottesley Road, towards its junction with Furness Road, and accepted the proposed conversion in that context.
The rear dormer measures approximately 5.4 metres wide and 2.9 metres high in the officer’s assessment. It sits above the eaves, below the ridge and in from the new gable end. That last offset keeps the dormer separate from the side gable when viewed from the flank. Two rooflights serve the front roof slope.
The construction photograph now shows the dormer’s timber framing and OSB sheathing, with its two window openings formed beneath the temporary scaffold roof.
Engineering coordination
Structural Engineering
We prepared the structural drawings and calculations alongside the planning and Building Regulation work for Wrottesley Road.
The construction photographs show the structure at the junction between the retained house and the additions: steel beams and columns below the timber floors, new masonry beside the existing staircase, and roof framing around the retained chimney. The close-up of the bolted connection records one of those interfaces before the finishes cover it.
Our house structural engineer service formed part of the same appointment as the extension and loft design.
Technical compliance
Building Regulations
Technical information for the extensions and loft
ACDS prepared the Building Regulation drawings for the extension and loft works alongside the structural information.
The relationship between retained construction and new work runs through the project, from the existing staircase and adjoining blockwork to the timber floors and roof around the retained chimney. The technical drawings sit alongside the structural foundation and framing plans shown in the gallery.
Reading the project gallery
The front visualisation shows the intended external appearance. The existing and proposed plans explain the changes to the house, while the construction photographs record the steelwork, masonry, roof and dormer before finishes are added.
Consent and delivery
Project Outcome
Planning permission granted
Brent Council granted planning permission for the side and rear extensions, hip-to-gable roof alteration, rear dormer and two front rooflights on 3 July 2026, under application 26/0882, subject to the conditions in the decision notice.
The officer accepted the combined extensions and their relationship with neighbouring properties. No consultation comments were received.
Construction in progress
Work is underway, with the structure and roof construction recorded in the gallery. For the steps that can follow an approval, read our guide to discharging planning conditions.
For a related combination of extensions and roof alterations, explore 77 Wood Vale. You can also browse our Brent project portfolio.
Considering an extension and loft conversion together? Book a project consultation to discuss the design, planning and technical drawings.
