Skip to main content

Northwood HA6 · Bathroom renovation

Bathroom renovation in Northwood

Side windows, flues and pipes, and The Glen’s floors

In Northwood, the outside face of a bathroom can matter as much as its fittings. Hillingdon’s committee papers show how officers have treated bathroom windows facing neighbours and roof flues, its documents record original downpipes and older advice on vent pipes, and The Glen’s maisonettes have lease terms of their own. This page covers those points, then building control, adapted bathrooms and a single room on its own.

Book a free feasibility visitSee typical costs

Serving Northwood from our Hampstead studio · NW3 6DN
020 7101 3168

Start here

Bathroom renovation in Northwood at a glance

Pipework that shows from outside is the local thread to follow. Hillingdon’s 2019 appraisal of the town centre conservation area pictures a cast iron downpipe among its traditional materials, records original downpipes surviving on the roughcast render of 21-25 Maxwell Road, and notes that the Coral building, built in 1926, is dated on a downpipe. It sets no rule on pipework, but those pipes are part of the area’s recorded character. In the Northwood-Frithwood conservation area, the council’s November 2009 leaflet told residents that vent pipes on a principal or side elevation, or on one fronting the highway, would require permission; that was its own summary of the rules then.

Hillingdon: Northwood Town Centre, Green Lane Conservation Area Appraisal, adopted September 2019 (PDF) · Hillingdon: Northwood-Frithwood Conservation Area leaflet, November 2009 (PDF)

For the whole area, including conservation areas, permissions and working hours, read our Northwood renovation guide.

Approved guide prices

What does a bathroom renovation cost in Northwood?

A typical bathroom renovation in Northwood costs £10,000–£30,000 excluding VAT. The final price depends on the scope, the specification and the complexity of the room, and a fixed written price follows the visit and the design.

Scope of workTypical cost
Typical bathroom renovation£10,000–£30,000

The figure excludes VAT. A standalone bathroom gets its own room-specific quotation; try the cost calculator for a first figure.

The buildings

Bathrooms in Northwood’s maisonettes and conversions

Two Northwood records bear on bathroom work in maisonettes and conversions: The Glen’s original leases, and a recommended condition on a bathroom window in a Northwood conversion. Each belongs to its own building and date.

At The Glen, the council’s March 2008 appraisal records the estate’s own lease terms: the first owners of the maisonettes were granted 999-year repairing leases from 24 June 1958 which, among their terms, provided for no works of “alteration or addition whatsoever”, and no “cut or injury to any main wall, timber, girders, ceilings, roofs or floors”, without the landlord’s previous written consent. A new waste or soil route through a floor, joist or main wall is the kind of work that clause covered. Check whether your own lease still reads that way, and ask the residents’ company.

Hillingdon: The Glen, Northwood Conservation Area Appraisal, March 2008 (PDF) · LEASE: alterations and home improvements

Bathroom windows facing a neighbour have come up in Northwood planning decisions. In 2011, when the North Planning Committee approved the extension and conversion into flats of a building on Eastbury Road, the officers’ report had recommended a condition requiring a bathroom window facing a neighbour to be glazed with permanently obscured glass and non-opening below 1.8 metres above the internal floor, to prevent overlooking. Hillingdon’s current guidance is similar: side-wall windows in new extensions should be high level, non-opening below 1.8m above internal floor level and fitted with obscured glass.

Hillingdon: planning applications search (the council's planning register) · Hillingdon Local Plan Part 2: Development Management Policies, adopted 16 January 2020 (PDF)

Permissions and local rules

Windows, flues and drains in Hillingdon’s decisions and rules

Shower rooms behind obscured side windows

What did officers recommend on one approved scheme?

In 2012 the North Planning Committee voted five to one to approve “as per the officer’s report” an extension scheme for a house on Grove Road, including a basement; its plans showed shower rooms and a bathroom behind obscure-glazed side windows. Officers recommended conditions requiring windows facing neighbours to be permanently obscured and non-opening below 1.8 metres, and removing permitted development rights for further openings in the extension facing them. The report records Thames Water asking for protection against backflow, such as a non-return valve, assuming sewers may surcharge to ground level in storms: a request, not a condition.

Hillingdon: planning applications search (the council's planning register)

Roof flues serving a shower room

Has Hillingdon accepted roof flues for a bathroom?

When alterations to the rear extension of a house on Greenheys Close came to the North Planning Committee in 2017, objectors raised the visual impact of two roof flues, shown on the plans as serving a shower room and a boiler. Officers found them typical of the flues commonly seen on residential properties, with a minor overall visual impact on which refusal could not be justified, and the committee unanimously approved, with an additional condition on a side window. The report cited no conservation-area or local-character policy, so do not assume the same answer in such areas.

Hillingdon: planning applications search (the council's planning register)

Building control for one room

Which approval route suits a bathroom?

Hillingdon’s building notice route issues no plans approval, and the council strongly recommends not using it unless, among other things, your builder has the ability to complete the work successfully. Work can start after 48 hours’ notice, the application needs a site location plan at 1:1250 showing the size, position and drainage of the building, and you must submit a Notice of Completion within 5 days of finishing. A building notice cannot be used for building work over or close to a public sewer, so find where the public sewer runs before choosing the route.

Hillingdon Building Control: apply for building control approval (building notice route)

A bathroom below ground

What changes if the bathroom is in a basement?

For basements, Hillingdon’s plan says consideration should be given to adding a positive pumped device so they are protected from sewer flooding, and the council will require a flood risk assessment for subterranean development in areas at risk of flooding or where watercourses are present. Its Local Flood Risk Management Strategy 2015 explains sewer flooding as the network exceeding its capacity, for example when too much surface water enters the sewers, silt builds up or tree roots break through pipes, and says public sewers are the responsibility of the water companies.

Hillingdon Local Plan Part 2: Development Management Policies, adopted 16 January 2020 (PDF) · Hillingdon: Local Flood Risk Management Strategy 2015, report dated February 2016 (PDF) · Check long-term flood risk in England

Working hours, skips, parking and the conservation area maps for the whole area are in our Northwood guide. Local guidance checked ; requirements depend on the address, the building and the complete proposal.

What the work covers

What a Northwood bathroom renovation covers

The waste route, traced and tested

Every fitting’s waste is drawn back to the soil stack or drain with its fall before tiles are chosen, and existing pipes are tested or inspected by camera where their condition is in doubt. Where a route must cross a joist or pass through a wall, the drawings show how, and in a flat or maisonette that is agreed under the lease before any floor is opened.

Air out and light in

The extract fan, its duct and the outlet position are drawn with the room, keeping vents off the front and street-facing walls where the structure allows. Where the bathroom has a window facing a neighbour, obscure glass and a fixed lower section are priced from the start rather than added after a neighbour or an officer raises it.

Waterproofing, wiring and records

Wet areas get a waterproof layer on floor and walls before tiling, with junctions and pipe entries sealed, because in a flat a leak reaches the home below. Electrical work near the bath or shower is designed with the room, and the scope names who provides each certificate or completion record, so the paperwork is complete when you come to sell or let.

How we work

How we run a Northwood bathroom renovation

  1. Visit

    We see the room, trace where the stack runs, and check which floor it is on and what lies beneath.

  2. Survey

    The drainage falls, the extract route and the floor build-up at the door are measured before a layout is drawn.

  3. Design

    The layout, waterproofing and storage are drawn; where a floor or wall changes, our own architects and structural engineers design it.

  4. Price

    You receive a fixed written price once the design and fittings are agreed.

  5. Installation

    The dates, and any days without a working bathroom, are agreed before work starts.

  6. Handover

    Testing, then care notes for the finishes and fittings. Completed work carries a 12-month defects-rectification period under the JCT contract terms.

Real projects, clearly located

Examples of our bathroom renovation work elsewhere in London

None of these projects is in Northwood. Each card names where the work was done, so you can judge the finish and the approach before you brief your own.

Your brief

Before you ask for a quotation

  1. Where the room sits

    Tell us the floor the bathroom is on, what lies directly below it, and whether it replaces a bathroom or adds one. For a maisonette at The Glen or any other flat, say who the freeholder is.

  2. What shows outside

    Photograph the wall where a soil pipe, vent or extract outlet would leave the building, and any window that faces a neighbour or the street, so the route and the glazing can be settled with the layout.

  3. Who will use the room

    Say which fittings matter to you and whether someone with limited mobility will rely on the room. If a council grant may pay for an adaptation, say so at the start, because the grant’s own assessment and approval come before any work.

Ready to take the next step? Send the address and a short outline of the work.

Book a free feasibility visit

Questions before you begin

Bathroom renovation in Northwood: questions

Can one Northwood bathroom be a project on its own?

Yes. We welcome a standalone bathroom renovation as a project in its own right, whether it replaces a worn bathroom, adds a shower room or turns a spare room into an en-suite. One room still raises questions about the waste route, extract air, waterproofing over the room below and which approvals apply, so send its measurements, photographs and what lies beneath it.

Can a garden building have its own bathroom?

Not in a residential outbuilding, under Hillingdon’s adopted plan. Among its criteria for outbuildings, Policy DMHD 2 says primary living accommodation such as a bedroom, bathroom or kitchen will not be permitted, and the supporting text explains that the council treats these facilities as primary accommodation located within the main house. As a general guide, it adds, an outbuilding should be no greater than 30 square metres. Plan a new bathroom inside the house instead.

Hillingdon Local Plan Part 2: Development Management Policies, adopted 16 January 2020 (PDF)

Can a grant help pay for an adapted bathroom in Northwood?

Works under Hillingdon’s Disabled Facilities Grant include facilitating access to a bathroom. A social services occupational therapist decides what is necessary and appropriate; works must be simple and cost effective and will mainly be within the existing footprint, with an extension considered only once all other options are explored. It is means tested, except for council-owned homes, with a maximum set on the council’s page. Among its conditions, the landlord’s permission must come before approval and applicants must mean to stay at least the next five years. Starting work before formal approval cancels the application.

Hillingdon: Disabled Facilities Grant

Who pays for a leak from my bathroom pipes?

In a private block, your lease decides. For Hillingdon Council’s own leaseholders, the January 2026 booklet says that normally all repairs inside the flat are the leaseholder’s, including sanitary fittings such as toilets and basins and any services that serve only that flat, so a leak from a pipe in the flat is the leaseholder’s responsibility. Who looks after pipes shared with other homes is a question to settle with the landlord before work starts.

Hillingdon Council: information for Hillingdon Council leaseholders, factfile 119, January 2026 (PDF) · LEASE: alterations and home improvements

Do Hillingdon’s accessible-bathroom standards apply to my refit?

Not as rules. The Accessible Hillingdon SPD, adopted in September 2017, says every new dwelling is to have a bathroom on the same floor as the principal double bedroom, with a WC, basin and bath and the required clear access zones. In new homes required to be wheelchair adaptable or accessible, a room with a level-access shower is to be a wet room, walls are to take grab rails and seats, and soil stacks should sit away from the pan, and must be on a side wall where there is no other practical alternative.

Hillingdon: Accessible Hillingdon SPD, adopted September 2017 (PDF)

Can a soil and vent pipe go on an outside wall without permission?

For a house, national Class G rights allow a new or replacement soil and vent pipe or flue without planning permission, subject to limits including that it must not rise 1 metre or more above the highest part of the roof and, in a conservation area, must not be fixed to a wall or roof slope that both fronts a highway and forms the principal or a side elevation. A condition on an earlier permission may have removed the right, and flats have no such right at all, so check first.

Householder permitted development technical guidance

How much does a bathroom renovation cost in Northwood?

A typical bathroom renovation in Northwood costs £10,000–£30,000 excluding VAT. The final price depends on the scope, specification and complexity of the project. We give a fixed written price after the visit and the design.

Book a free feasibility visit

Talk to us about your Northwood bathroom

Tell us the address and what you want to change in your Northwood bathroom. We reply within one working day, Monday to Friday, 8am to 6pm.

Or call 020 7101 3168. We serve Northwood from our studio at Unit 3, Palace Court, 250 Finchley Road, London NW3 6DN.

Use the full contact form instead

Keep exploring

More for your Northwood project

Bathroom renovation in nearby areas

Chat with us!