Planning a Winter-Ready Renovation: The Dutch Calendar

The call comes in the second week of October. There is condensation running down the inside of the bedroom window, the north wall smells faintly of damp, and the first proper heating bill has landed. Can we come and sort it out before Christmas? Sometimes we can. But the honest answer is usually that the thing they want done properly this winter was a decision for March, and not because of any preference of ours. It is arithmetic.

Work backwards from the first cold week

Set a target: the house finished and commissioned by the end of November. Then count backwards through everything that has to happen first, using real Dutch lead times rather than optimistic ones, and see where you land. Most people are surprised by how far back the start date moves.

The lead times that actually set the date

Indicative ranges for Amsterdam and Noord-Holland. They move with the market, and they all stretch in autumn because everyone else has had the same idea at the same moment.

• Wooden or aluminium frames made to measure: commonly 6 to 12 weeks from final measurement, and final measurement only happens once the design is fixed. Replacing the glazing in an existing frame is faster, typically 2 to 4 weeks.
• A heavier or three-phase electrical connection through the grid operator. This is frequently the longest item in the whole project. Application to execution routinely runs into months, and there is no way to buy your way up the queue.
• Heat pumps: the unit may be weeks, the installer's diary is often months, and autumn is exactly when it is worst.
• Bespoke joinery 6 to 12 weeks, a kitchen 8 to 14. Lacquered finishes take longer in cold, damp conditions, because the workshop has to control its own climate before it can spray.
• Large-format tiles and natural stone: 3 to 8 weeks, longer for anything not already in a Dutch warehouse.
• Scaffolding plus the municipal permit for occupying pavement or a parking bay: allow several weeks for the permit alone, more in the centre.
• An omgevingsvergunning where one is needed: the standard procedure runs eight weeks with a possible extension, and the extended procedure considerably longer. When you actually need one is set out in our guide to permits, monuments and VvE approval.
• VvE consent, the sharpest constraint of all. Many associations decide at a single annual meeting. Miss the agenda deadline and you either wait a year or pay for an extraordinary meeting that still needs notice.

Bouwvak, and the shadow it casts

The Dutch construction industry takes a coordinated summer holiday, staggered by region, of roughly three weeks; in the north it usually falls from late July into mid-August. The three weeks are not the problem. The problem is the shadow on either side. Factories stop taking orders before it and restart with a backlog afterwards, so an order placed in early July easily becomes a September delivery, and the subcontractor you were counting on in August is booked solid through the first fortnight of September catching up on everyone else.

The same thing happens in miniature at the end of December: two weeks of closed sites and stopped production, at exactly the moment a project that slipped in autumn is trying to recover.

Weather is not an excuse, it is a specification

Some work genuinely cannot be done well in a Dutch late autumn. Knowing which is worth your time, because it lets you tell the difference between a contractor managing your expectations and a contractor managing their diary.

• Exterior paint and coatings: most systems want surface temperatures above roughly 5 degrees and falling humidity. In a Dutch October the dew point arrives in the late afternoon, which means a second coat applied at four o'clock is a second coat that will fail.
• Screed and plaster both need warmth and air movement to dry. A cement screed wants roughly a week per centimetre for the first four centimetres, and in an unheated house in November it takes longer than that. Laying a wood floor on a screed that is not dry is one of the most expensive mistakes in interior work.
• Wood floors want the house at a stable relative humidity, broadly 45 to 60 percent, with underfloor heating commissioned and taken through its heating-up cycle before anything is laid.
• Facade work, pointing and external insulation: frost is a hard stop, not a slow-down.
• Roofing membranes and bitumen have temperature windows, and wind limits the days on which anyone can work safely at height.
• Ground and garden work: a waterlogged Amsterdam garden in November is not a site.

What autumn and winter are genuinely good for

None of this means you should avoid renovating in the colder half of the year. Inside a heated, weather-tight house, winter is often the better season. Teams are easier to book than in the September rush, kitchens, bathrooms, joinery, acoustic work and interior floors are indifferent to what is happening outside, and you are not surrendering your garden and your summer to a building site. We have made that case at length in the argument for renovating in autumn and winter.

The real distinction is between envelope and interior. Envelope work, meaning windows, facade, roof and external insulation, wants the mild and reasonably dry part of the year. Interior work does not care, provided the house is heated and the programme allows time for things to dry.

A workable calendar for a winter-ready house

• March and April: survey. Look at the house while the damage from the last winter is still visible, settle the scope, and get your item onto the agenda for the VvE spring meeting.
• April and May: design and specification, quotations, and the permit application if one is needed. Start the grid connection application now if the power supply is changing.
• May and June: order the long-lead items. Frames, glazing, joinery, tiles, the heat pump. Book the contractor's slot; by late June the good autumn slots are gone.
• July and August: bouwvak. Plan around it deliberately, either as a deliberate gap or as a window for interior work that needs no deliveries.
• September and October: envelope work while the weather still allows it. Windows, facade, roof, insulation, and exterior paint early in the window rather than late.
• October and November: interior work, then commissioning. Heating balanced, ventilation flows measured, floors laid on a substrate that is genuinely dry.
• December: the heating season starts in a finished house.

The spring inspection: what to actually look at

A house tells you in spring what the winter did to it. In full daylight, a few weeks after the heating goes off, walk round and look at:

• The north and west facades: pointing, hairline cracks, salt bloom, and paint that has lost its film on the weather side.
• Window and door joinery, particularly the bottom rails, the glazing beads and the drip edges. This is where Dutch timber frames fail first, and catching it early is the difference between repair and full replacement, which is the judgement we make most often on windows and frames.
• Flashings, gutters and downpipes, including the joints at the parapet and around any dormer.
• Inside: the reveals and the corners of external walls. Mould and dark shadowing mark cold bridges and inadequate ventilation.
• The crawl space: humidity, standing water, and the condition of insulation and pipework.
• The meterkast, to see whether any headroom is left for what you are planning.

That is an hour's work, and it turns a vague worry into a scope, which is the thing a contractor can actually price.

One financial note

If the plan includes insulation or a heat pump, check the current conditions of the ISDE scheme with RVO before you commit rather than afterwards. The budget is set annually, the qualifying measures and amounts change from year to year, and applications for insulation are made once the work is completed and paid for. Planning ahead gives you time to confirm that what you are ordering actually qualifies, which is a far better position than discovering in December that a measure missed a condition by a detail. The same logic applies to combining measures, which we cover under energy and eco renovations.

Planning a season ahead is not really about booking a contractor early. It is about giving permits, approvals, lead times, drying times and the weather the room they each need, so the work happens at a pace that produces quality rather than callbacks. If you would like winter to be simply another season rather than a source of concern, the useful month to start is the one you are in. Get in touch and we will tell you honestly whether the calendar still works for this year, or whether we should be planning for the next one.