At 393 Pinner Road in North Harrow, the approved design brings several parts of the house into a coordinated plan: a rear extension for cooking and dining, a garage converted into a separate reception room, a reworked loft suite and a gym in the garden. Each space has a distinct role, giving the household places to gather as well as rooms where activities can happen independently.
The scheme forms part of our residential architectural work in Harrow. It combines householder planning permission with a lawful development certificate for the roof alterations and garden building.
A social kitchen with a separate cooking space
The rear extension projects approximately four metres and replaces a fragmented arrangement with a clearer sequence of seating, kitchen and dining areas. A dry kitchen sits in the main social space, while a separate wet kitchen provides another preparation and cooking area alongside it. A glazed sliding door connects the two, allowing them to be used together or separated.
The dining table is placed at the garden end, beside broad sliding doors. Rooflights bring daylight into the deeper parts of the plan, including the utility area, while a wide rooflight sits above the main kitchen zone. These openings are designed to support the rooms within the footprint as well as brighten the new extension. Our approach to house extension design considers how the new and existing spaces will work together.
Keeping useful rooms alongside the open space
The existing front living room remains separate. Beside it, the garage conversion creates another reception room reached from the hall. That gives the layout an additional place for quieter activities without everyone needing to share the kitchen and seating area.
A ground-floor shower room and utility room occupy the side of the plan between the reception room and wet kitchen. Their position keeps everyday washing and household tasks close to the main living areas. The proposed roof changes bring the garage and side extension into a consistent low roof profile with the rear addition.
A more considered loft suite
The roof design replaces the hipped end with a gable and introduces a rear dormer. Within the existing loft accommodation, the new arrangement provides a bedroom, en suite and walk-in wardrobe, with lower spaces used for cupboards and storage. Two front rooflights serve the roof space, and the side window is shown with obscured glazing and restricted opening below 1.7 metres.
The first-floor layout also includes an en suite beside the front bedroom and a replacement stair to the loft. Considering the stair, storage and bathrooms together is an important part of loft conversion planning, because these elements determine how comfortably the upper floors can be used.
A dedicated garden gym
At the rear of the garden, the proposed timber-clad outbuilding contains a gym, shower room and storage. Bi-folding doors face the garden beneath a small roof overhang. Its maximum height is shown as 2.5 metres, and the plan retains the nearby existing tree. The gym gives exercise its own setting away from the main reception rooms.
One design, two planning routes
Harrow Council granted householder permission PL/1481/26 on 28 July 2026 for the rear extension, garage conversion, roof alterations to the side accommodation and external changes. The separate certificate PL/2043/26, issued on 3 August 2026, confirms the proposed gable, dormer, rooflights, side window and garden gym as lawful development. Our permitted development and certificate service explains how this route is assessed for individual properties.
The householder permission requires matching external materials, restricts additional openings in the side elevations and prevents use of the extension roof as a balcony or roof garden without further permission. These qualifications form part of the approved scheme and help protect neighbouring amenity.
To explore how an extension, loft alteration or garage conversion could work together in your home, arrange a project discussion with Detailed Planning.
Project Gallery
