Commercial to residential conversion creating 2 flats in Brent
At a glance
Project type
Commercial to residential conversion | Small residential development | Urban intensification
Location
Brent, London
Brief
Change of use of a vacant ground-floor commercial unit, extension and reconfiguration of the upper maisonette, and upgrade of the existing building to create 2 new residential flats.
Outcome
Full planning approval secured in February 2026 following pre-application advice in September 2025.
Architectural services provided
Feasibility and design proposals, pre-application advice, planning submission, Building Regulations drawings, Party Wall information and construction-stage support.
Conversion and extension of a vacant corner commercial unit
This project tested the conversion of a vacant Class E corner unit in Brent, together with extension and reconfiguration of the upper maisonette, to create 2 residential units within an existing mixed-use building.
GOAStudio was appointed in 2025 to assess the potential of the site, prepare feasibility and design proposals, and take the scheme through pre-application and planning.
The proposal combined change of use, extension and retrofit works within an existing building in a predominantly residential setting.
Site and planning position
The site sits on the corner of Crownhill Road and St John’s Avenue. The commercial unit occupies the ground floor, with a maisonette above at first-floor level.
The surrounding area is predominantly residential. The site is not within a conservation area and is not subject to an Article 4 Direction.
That gave the project a relatively clear basis for testing residential use at ground-floor level.
The focus therefore shifted to layout quality, frontage treatment, amenity provision and the overall coherence of the residential scheme rather than the principle of residential use itself.
Development brief
The brief was to test the maximum reasonable potential of the site while maintaining a workable planning position and a good standard of accommodation.
The main points under review were:
• change of use of the vacant commercial unit to residential
• extension and reconfiguration of the upper maisonette
• creation of 2 dwellings within the existing building and its immediate footprint
• redesign of the former shopfront and frontage
• improvement of the building fabric through a retrofit-led approach
Pre-application advice was sought in September 2025, followed by full planning approval for 2 residential units in February 2026.
Design and planning response
The design response focused on adapting the building in a way that supported residential use without losing coherence at street level.
Frontage strategy
The existing shopfront area was redesigned so that the ground floor could read more convincingly as residential accommodation while still acknowledging the building’s former commercial use. The material strategy proposed zinc together with dark grey or black brickwork to define the former commercial zone while matching the pattern and finish of the existing red brickwork. This was intended to provide a more robust frontage in terms of sound insulation, thermal performance and access to light.
Rear extension
The existing rear extension was described as poor quality and was proposed for demolition and replacement with a new rear extension of similar scale, siting and size.
Roof extension
The upper dwelling was extended through a hip-to-gable roof extension, together with a rear dormer, side dormer, rooflights and recladding of the roof with matching slate or tiles. These works allowed the upper maisonette to be reorganised as a larger family-sized dwelling.
Amenity, cycle and refuse provision
The front yard area was remodelled to provide residential amenity space together with cycle storage, refuse storage and permeable paving.
Side elevation and window upgrades
A new side window was introduced in a position aligned with the existing window pattern, size and setting. Window replacements were proposed in double- and triple-glazed aluminium frames to improve thermal performance. The brief also states that the proposals were developed to remain in keeping with the surrounding residential character while not affecting the access or amenity of adjacent properties.
Retrofit and building-performance strategy
The project was approached through a retrofit methodology, reflecting the fact that a substantial part of the existing building fabric was being retained and upgraded. The environmental strategy focused on improving thermal performance, internal comfort and long-term durability.
Measures included:
• internal wall insulation to existing walls
• insulation to suspended timber floors and existing roofs
• reduction of thermal bridging
• improved airtightness through rendered internal surfaces and sealed junctions
• double- and triple-glazed aluminium-framed windows and doors
• natural ventilation and cross-ventilation to habitable rooms
• decentralised mechanical ventilation with heat recovery
• rainwater collection
• lightweight sedum roof to the new rear extension
• low-water-use sanitary ware
• permeable paving to the front yard
• LED lighting and smart controls
• reuse and upgrading of a substantial part of the existing building fabric where possible
• use of durable, lower-carbon and locally sourced materials where possible
Proposed accommodation
The approved accommodation comprised:
• Ground floor: 2-bedroom, 4-person flat, 73.4 sqm
• Ground-floor entrance, first floor and loft: 3-bedroom, 5-person flat, 94.08 sqm
The proposals were developed within the constraints of the existing building, with the brief noting that every effort was made to meet and exceed the relevant London Plan space requirements for both the overall dwellings and the individual rooms.
The resulting arrangement allowed the site to move from underused mixed-use accommodation to a more coherent residential configuration with two policy-compliant homes.
Explore similar development projects
This Brent scheme sits within GOAStudio’s wider experience of small residential developments, conversions, feasibility studies and planning-led design for developers.
See our property development architectural services page for more on how we support developers, landowners and small urban sites across London.
You can also explore related case studies including:
- New-build flats feasibility study in Lewisham
- Outline approval for 4 homes and mixed-use feasibility in Newham
- Penthouse alterations and refurbishment development in St James Park, Westminster SW1H
- New build house development planning approval Southwark
- Highgate new house development project
Outcome and delivery
The scheme progressed from feasibility work in 2025 to pre-application advice in September 2025 and then to full planning approval in February 2026 for 2 new residential units. GOAStudio’s role continued into Building Regulations drawings, Party Wall information and support during construction through to completion.
Application to similar sites
This project is relevant to sites involving:
• vacant or weak-performing commercial units in residential areas
• corner properties with underused upper accommodation
• small development opportunities that depend on extension and reconfiguration rather than full redevelopment
• schemes where change of use is only one part of the overall site strategy
• projects where retained fabric and upgraded performance need to be considered together
This project is a useful reference for mixed-use corner buildings where the development opportunity depends on combining change of use, extension, layout reorganisation and building-performance upgrades into one coherent planning strategy.
For broader regional advice on homes, conversions and small residential developments, see GOAStudio’s West London residential architect page.
Looking at a similar site?
If you are assessing a vacant commercial unit, mixed-use building or small urban site with residential development potential, early architectural advice can help establish a realistic basis for the next stage.
We provide architectural services for residential projects in the following London Boroughs:
Barnet, Camden, Enfield, Hackney, Hammersmith and Fulham, Haringey, Islington, Kensington and Chelsea, Lambeth, Lewisham, Newham, Tower Hamlets, Waltham Forest, Wandsworth, Westminster
We specialise in
- Greener homes
- Retrofit and energy efficiency for older and traditional buildings
- Conservation areas
- Listed Buildings
- Homeowner architectural services
- Property developments architectural services
GOAStudio London residential architecture limited.
86-90 Paul Street, EC2A 4NE, Hackney
Chestnut Avenue South, E17 9EJ, Waltham Forest
t: 0203 984 3005
