Is it worth having a media wall?

Two different questions hide inside that one. Whether the room is worth improving, only you can answer. Whether the build pays you back on sale has a firmer answer: it does not. A RICS surveyor values from comparable sales, and there is no comparable line for a media wall, so the valuation figure does not move. A well-built one helps the room show, which can shorten a sale rather than lift the price. Anyone quoting you a percentage return has invented it.

So the money question is the price you pay, not the price you recover. Our range runs £3,500 to £7,000, and the tier most clients pick sits at £4,500 to £5,500 — framework, recess, certified electrics, plaster, paint, joinery either side, lighting, fixed after the survey. The cheap national averages you see quoted elsewhere do not survive London labour plus a certificated installation. A quote under our floor has something missing, and it is usually the electrical sign-off or the plywood behind the mount.

This is the part nobody writes about. Part P of the Building Regulations has covered domestic electrical work since 1 January 2005. Only some of that work has to be notified to Building Control — a new circuit, a consumer unit change, or anything in a special location such as a bathroom — and a media wall usually runs new sockets off an existing circuit, so it often sits outside notification. That does not let it off. It still has to be designed, installed and tested to BS 7671, and it ends up buried behind a plastered surface where nobody can look at it again. When you sell, the Law Society's TA6 Property Information Form asks you to declare electrical work carried out at the property since 2005 and to hand over the certificates that go with it. Your buyer's solicitor will ask for the paperwork on that wall, and a seller who answers TA6 loosely can be pursued for compensation after completion.

Without a certificate every remedy costs money: a retention held back from the sale price, an indemnity policy, a price reduction, or, where the work was notifiable and never notified, a regularisation application to the council for work already covered over. The real risk of a media wall is a form, not a matter of taste. Every build we hand over is inspected and signed off against BS 7671, the 18th Edition Wiring Regulations, by our in-house NICEIC-approved electrician, and that certificate carries six years of insurance-backed cover. It is the one part of the wall the next owner's solicitor will actually ask about.

Five situations where we say no, or say wait. Moving inside about eighteen months: the certificate protects you, the joinery will not repay you, and the money does more in the kitchen. A leaseholder without written freeholder consent should not let anyone start; consent takes two to four weeks, and verbal permission is worth nothing in a conveyancing pack.

Under a 2.6m ceiling a deep recessed fire crowds the room, so step down to a slim wall-effect unit and a 55-inch screen. An 85-inch screen wants three to three and a half metres from sofa to wall; squeeze one into a shorter room and you sit too close to enjoy it. And if you want the fire to heat the room, buy a different product: one to two kilowatts takes the chill off fifteen to twenty square metres in mild weather and stays supplementary to your central heating. We would rather lose the enquiry than build something you resent in a year.