A total renovation is often the biggest project of a lifetime. Budget and schedule overruns rarely come from a single problem: it is almost always the same mistakes, made at the start. Here are the seven that cost the most, and what to do instead.
In an old building you never know everything until the walls are open: a damaged beam, lead pipes, wiring that no longer meets standards, damp behind a lining. A budget calculated to the cent does not survive the first surprise.
Do this instead: keep a reserve of 10 to 15% of the cost of the works, up to 20% for an old house that has never been renovated. Ask for a quote itemised by trade so you know exactly what is and isn't included.
Redoing a kitchen, a bathroom or the painting usually needs no permit. Removing a load-bearing wall, changing the façade, changing the number of dwellings or extending does. Work done without a permit can block a sale or lead to an order to restore.
Do this instead: list the works and check them with your municipality's planning department (or the omgevingsloket in Flanders) before signing anything. If an architect is required, build their lead time into the schedule.
The logical order is: demolition, structural work, roof and windows, electrics and plumbing, insulation, plastering, screeds and floors, interior joinery, painting and finishing. Painting before the cables are pulled, or laying parquet before plastering, means starting again.
Do this instead: ask for a written schedule in this order, especially when several trades are involved.
In Belgium, renovated wiring must be inspected by an approved body before it is used, and the report is requested when the home is sold. Half-renovated wiring, or wiring done by someone who doesn't know the AREI/RGIE rules, can be very expensive to fix after the finishes.
Do this instead: plan the full renewal of the fuse board and circuits from the start, with the compliance inspection included in the quote.
A well-insulated, airtight house becomes damp if the air is not renewed: condensation, mould, blackened joints. It is one of the most common problems after an energy renovation.
Do this instead: plan ventilation (at least extraction in wet rooms, ideally a controlled ventilation system) together with the insulation and new windows.
Cheap shower waterproofing or a cheap roof membrane looks economical on the quote, and costs twice as much when everything has to come out. Conversely, there's no need for top of the range everywhere.
Do this instead: invest in what is hidden and hard to redo (waterproofing, insulation, pipes and cables); save on what is easy to replace (light fittings, taps, decorative paint).
A plumber, an electrician, a tiler and a plasterer who don't talk to each other means lost days between each visit and unclear responsibility when something goes wrong.
Do this instead: give coordination to one person responsible for the schedule and the result, an architect or a general contractor.
A successful total renovation is decided before the first hammer blow: a detailed quote, a contingency, checked permits, a clear order of works and one person coordinating.
CULA carries out complete renovations in Brussels and the surrounding area with a single point of contact, from quote to handover. Free visit and detailed quote within 48 hours: request your quote.