DRAKEFIELD HOUSE
Side-Return Extension & Whole-House Refresh
Hornsey / Crouch End, North London. Completed November 2024
INTRODUCTION
Studio MASS delivered planning consent, the full Building Regulations package, Party Wall matters and construction monitoring for a side-return extension and whole-house refresh of a Victorian terrace in Hornsey, North London. The project reworked 38 m² across a new kitchen/dining extension, a relocated downstairs WC, and a reconfigured first-floor bathroom and utility room. Construction cost £140,000, against a working budget of £150,000. Completed November 2024.
WHAT THE PROEJCT INVOLVED
The clients, a couple working in the television and film industry with two young children, had recently bought a Victorian terrace in Hornsey when they appointed Studio MASS. The existing kitchen was small, narrow and cramped, with no space for the family to sit down together, and the adjoining middle room was dark and cut off from the rest of the ground floor. A level change between the main house and the rear kitchen made it unclear how the two areas could ever properly connect while keeping daylight through.
Studio MASS's scope covered the full technical journey: submission of a prior approval application for the extension, the complete Building Regulations package, Party Wall matters with an adjoining council-owned property, and construction monitoring through to completion. Design work began in August 2023. The prior approval application was submitted in early October 2023 and approved six weeks later. Building Control was submitted in February 2024, and the contractor, a team Studio MASS has worked with across multiple projects, was on site from July to November 2024.
DO I NEED PLANNING PERMISSION FOR A SIDE-RETURN EXTENSION?
This project proceeded entirely under permitted development, using the "larger home extension" prior approval route rather than a full planning application. The council notified all fifteen adjoining premises, as the process requires, and received zero objections. Prior approval was confirmed within six weeks of the application being validated.
The extension itself removed an existing external WC block and infilled the full length of the side-return outrigger, a common and often more straightforward route to extra kitchen space than a full rear extension, provided the scheme stays within permitted development limits (in this case, extending 4.92 m beyond the rear wall, with a maximum height of 3.8 m and eaves at 2.85 m).
WHAT WAS ONE DESIGN MOVE THAT CHANGED HOW THE HOUSE WORKS?
A single, continuous run of glass. The new extension has a fully glazed roof, tied directly into a feature glazed window at the point where the extension meets the original middle room, designed as one uninterrupted glass element rather than two separate features. The effect reaches further than the kitchen itself: light floods into the previously dark, disconnected middle room too, which was reworked into the children's playroom.
The two spaces are linked by an internal opening, so a parent in the kitchen retains a clear sightline and can talk to children playing next door. It's connection without needing full open-plan living. A fire-rated pocket door was added at the kitchen threshold for the same reason: it stays open day to day, preserving the view straight through from the front entrance to the garden, and only closes automatically if the fire alarm activates.
WHAT STRUCTURAL WORK DOES A SIDE-RETURN EXTENSION INVOLVE?
Infilling a side return of this kind typically means removing more than just an external wall. At this property, the existing external WC block was demolished, the ground-floor section of the outrigger's side wall was removed, and the ground-floor section of a substantial chimney breast was taken out. New structural steelwork was introduced to carry the first floor above.
Removing the WC block meant finding it a new home: a downstairs WC was created under the stairs, along with a small storage area and access down to the floor void beneath the ground floor. The void was deeper than typical, owing to the property's level changes.
WHAT WENT INTO THE KITCHEN AND GARDEN CONNECTION?
The finished kitchen includes a built-in pantry, a full run of cabinetry, a feature island, and space for a large dining table beneath the glazed roof. Oak timber glazed doors, made in a traditional style, open the extension onto the garden.
Cost-conscious specification choices kept the budget under control without compromising the design: IKEA kitchen carcasses fitted with third-party fronts, an island sourced separately, and considered hardware and tile choices for the finishing details. The result reads as a considered kitchen, not a budget one.
WHAT HAPPENED ON THE FIRST FLOOR?
The first floor previously held a bathroom and a separate WC. Studio MASS repurposed and extended the WC into a proper utility and laundry room, which now also houses the boiler. This freed the original kitchen from that role entirely.
The rear section became a full family bathroom: a walk-in shower, a freestanding bath, and a double vanity unit, with the original sash window upgraded and refurbished to keep the room as bright as possible. A false wall conceals high-level plumbing runs for the new sanitaryware and doubles as built-in storage niches, which the clients specifically wanted.
WHAT HAPPEND WHEN YOUR PARTY WALL NEIGHBOUR IS THE COUNCIL?
The property immediately adjoining the side-return works was council-owned, which meant Party Wall notices were served on the local authority rather than a private homeowner, and negotiated through the council's appointed surveyor. The trigger wasn't the demolition of the WC block. It was the construction of a new flank wall on the line of junction, plus excavation within three metres of the neighbouring property.
A schedule of condition was carried out and a Party Wall Award agreed. In this instance, the process was straightforward: the council's surveyor was practical to deal with, and the main effort was working through the administrative steps required to get the award formally agreed, rather than resolving any substantive dispute
WHAT WOULD YOU DO DIFFERENTLY?
The one point of real friction on this project was Building Control. The local authority's building control team, not a private approved inspector, was used, and they were notably strict about the fully glazed roof and fixed-glazing system. Specific kite marks and calculated wind-resistance figures were required for the glazing, which meant considerable back-and-forth with the supplier to produce everything demanded. Coordinating the contractor's builders' work, forming the wall plate and related preparation, ahead of the glazing installer's programme added a further layer of sequencing.
That experience is one of the reasons Studio MASS now more often advises clients to appoint a private approved building control inspector rather than defaulting to the local authority, particularly on projects involving technically demanding elements like structural glazing. Beyond that friction, the project ran smoothly from planning through to completion.
THE OUTCOME
The family are settled into the space and use it daily. The kitchen and dining area under the glazed roof has become the hub of the house, with the children's playroom next door in constant use and in clear view from the kitchen. The garden connection, through the oak glazed doors, gets used as an extension of the kitchen in its own right.
Upstairs, the family bathroom is a genuine daily pleasure rather than an afterthought. A bath is positioned to look out through the refurbished sash window, and the walk-in shower was built taller than standard to properly suit one of the homeowners.
Before, this was a cramped, disconnected Victorian side-return kitchen with no room for the family to sit together, and a dark middle room cut off from the rest of the house. After, it is a light-filled kitchen and dining hub, visually and practically connected to a children's playroom and the garden beyond, delivered for £140,000 against a £150,000 budget.
Rathcoole Gardens demonstrates how a side-return infill, handled correctly from prior approval through to a technically demanding Building Control sign-off, can unlock significant extra space and daylight in a Victorian terrace without a full rear extension or a full planning application.
Studio MASS is an architectural technology practice based in London. This project was delivered by an architectural technologist, a specialist in technical building design and construction delivery, not a registered architect. All client details have been anonymised. The location is published as Tooting, South West London