Wind and watertight vs practical completion: the difference for finance
Wind and watertight and practical completion are two different points in a build, and lenders treat them as two different risks. This guide draws the line between a sealed shell and a finished, usable building, and shows what finance you can raise at each stage, what it costs, and when switching early is worth it.
Wind and watertight is the point in a build when the external envelope is sealed, meaning the roof is on, the windows are in and the external doors are hung, so the interior is protected from the weather while fit-out continues. Practical completion is a later milestone, where the whole building is finished bar minor snags, a completion certificate is issued and the scheme can be handed over and used. The gap between them is the internal fit-out and commissioning, and it carries real works risk, which is why a wind and watertight scheme prices between development finance and a clean exit bridge, while a certified practical completion unlocks the cheapest exit funding.
At a glance
- Wind and watertightExternal envelope sealed, interior unfinished
- Practical completionWhole building usable bar minor snags
- The gap between themInternal fit-out and commissioning
- Finance at wind and watertightFinish-and-exit or part-complete bridging
- Finance at practical completionA clean development exit bridge
- Exit bridge pricingIndicatively 0.65 to 0.95 percent per month
What a wind and watertight shell is, and what it is not
Wind and watertight is the stage in a construction programme when the external envelope of a building is closed up, so that wind and rain are kept out and the interior trades can work in the dry. In practice that means the roof is covered and made weatherproof, the external walls are up, the windows are glazed and fitted, and the external doors are hung. Once a scheme is wind and watertight, the shell protects the plaster, the joinery and the services being installed inside, which is why builders treat it as a key programme milestone and why development lenders often tie a drawdown to it.
What wind and watertight does not mean is finished. The internal fit-out is still to come: first and second fix, plastering, kitchens and bathrooms, decoration and floor finishes. The services are not commissioned, so heating, electrics and water are not signed off and tested. There is no completion certificate, no building control sign-off, no structural warranty in final form and, crucially, no practical completion certificate. A wind and watertight building cannot be occupied, sold with vacant possession as a finished home, or handed over. It is a weatherproof shell with a body of work still inside it.
The temptation is to read wind and watertight as most of the way done, because the building finally looks like a building. From a finance point of view it is not. The remaining fit-out is often where a scheme runs late or over budget, and the works still carry that risk. A lender pricing money against a wind and watertight scheme is pricing against a construction project that is part-built, not a finished asset.
What practical completion adds on top of a watertight building
Practical completion is the contractual milestone at which the works have reached the point where the property is ready to be occupied and put to its intended use, aside from minor snagging. Everything the wind and watertight stage left open is now closed. The internal fit-out is done, the services are commissioned and tested, and a certificate of practical completion is issued by the architect, contract administrator or employer's agent to log the date the works finished. That certificate is the document a valuer and a lender want to see, because it confirms the scheme has moved from a live construction site to a standing, usable building.
Reaching practical completion also sets off a chain of consequences that matter to funding. Some of the retention is returned, the defects liability period opens, and responsibility for insuring and bearing risk in the building shifts from the contractor across to the developer. Arriving with the certificate are a structural warranty like NHBC Buildmark on new homes, the building control completion certificate, valid Energy Performance Certificates, and the collateral warranties that hand a lender and a buyer direct rights against the contractor and the design team. We cover the certificate and the sign-offs in more depth in our guide at /learn/what-is-practical-completion/. The short version is that practical completion is the point where the works risk falls away and the paperwork proving it exists.
The two milestones side by side, and the finance at each
The clearest way to see the difference is to line up the state of the works, the certification, the insurance position and the finance available at each point. The table below sets that out. The figures are indicative and illustrative only, and nothing here is an offer of finance.
| Factor | Wind and watertight | Practical completion |
|---|---|---|
| State of the works | Envelope sealed, interior fit-out and services still to finish | Whole building finished and usable bar minor snags |
| Certification | No completion certificate; often a monitoring surveyor milestone only | PC certificate, building control sign-off and warranties issued |
| Insurance and risk | Contractor's all-risk cover; risk sits with the build | Risk and insurance pass to the developer at handover |
| Occupation and sale | Cannot be occupied or sold as a finished unit | Can be handed over, let or sold with vacant possession |
| Finance available | Finish-and-exit or part-complete bridging, staged for remaining works | A clean development exit bridge against the finished asset |
| Indicative pricing | Above a clean exit bridge, below development finance | Indicatively 0.65 to 0.95 percent per month |
The pattern that falls out of the table is that finance tracks the works. At wind and watertight the money on offer still behaves like construction debt, because there are works to fund and monitor. At practical completion the money on offer behaves like standing-asset debt, because the works are done. The route that bridges a part-built scheme through to completion and then sale is finish-and-exit finance, which we cover at /solutions/finish-and-exit-finance/.
Why exit lenders draw the line where they do
Exit lenders price for the risk they are actually taking, and the risk between a wind and watertight scheme and a practically complete one is different in kind. A clean development exit bridge is cheap, relatively speaking, because the building is finished: there is nothing left to build, the cost to complete is nil, and the lender is funding a sales period rather than a construction programme. That is why, on a completed scheme, an exit bridge is priced indicatively between 0.65 and 0.95 percent per month.
A wind and watertight scheme still carries works risk. The fit-out has to be paid for and delivered, it can run late or over budget, and until it is done the units cannot be sold. A lender funding at that stage is closer to a development lender than to a bridge provider: it may release money in stages against the remaining works, keep a monitoring surveyor involved, and hold back leverage to leave room for overruns. So it prices above a clean exit bridge. It sits below full development finance, because the hardest and most uncertain part of the build, getting the shell up and weatherproof, is already behind the scheme. The result is a middle band: dearer than an exit bridge, cheaper than the development loan it might replace.
Two schemes can be the same number of weeks from selling and be priced very differently. What moves the price is whether the works risk has gone, and that is what the practical completion certificate confirms. A lender is not paying for how finished a building looks; it is paying for the certainty that nothing is left to build.
How valuers treat a wind and watertight scheme
A valuation is where the difference between the two milestones turns into a loan amount. When a RICS valuer inspects a finished scheme at practical completion, the valuer reports the open market value of the completed units, which underpins the gross development value the exit facility is sized against. Leverage can then be released in full, indicatively as high as 70 to 75 percent of GDV, because the asset the lender is securing against actually exists in finished form.
A wind and watertight scheme is valued differently. The valuer will usually report the current, as-is value of the part-built asset, which reflects the land plus the works done to date, and separately set out the gross development value on the assumption the scheme is finished, with the cost to complete deducted. A lender lends against the lower, as-is position and retains funds for the outstanding works, releasing them as the fit-out is signed off. That is why a switch at wind and watertight advances less money than a switch at practical completion, even on the same scheme. The building is worth less to a lender when there is still a body of work standing between it and a sale. The numbers here are shown for illustration and are not an offer of finance.
The funding gap play: switch early or wait for the certificate
The practical question for a developer whose development loan is maturing is whether to refinance at wind and watertight or hold on for practical completion. Both have a cost, and the right answer depends on how much carry is at stake and how far off the certificate is.
Switching early at wind and watertight cuts the cost of carry sooner, because it clears the development facility, which is the most expensive money in the stack, and replaces it with finish-and-exit funding that prices below it. That matters when the development loan is running hot, at or beyond its term, or accruing default-style pricing. The trade-off is that the finish-and-exit facility prices above a clean exit bridge and advances less, because the works risk and the retained cost to complete are still in the picture.
Waiting for practical completion gets the developer the cheapest exit pricing and the highest leverage, because the certificate removes the works risk and lets the valuer report full GDV. The trade-off is that the developer carries the dearer development loan for longer, and if that loan has already matured, waiting can mean extension fees or pressure from the incumbent lender. The play, in short, is a straight comparison: the extra carry paid by waiting against the higher cost and lower advance of switching early. We can model both positions on a specific scheme, and the arithmetic behind the monthly cost sits on our tool at /tools/bridging-cost-calculator/. The wider picture on replacing a maturing development loan sits on our pillar page at /solutions/development-exit-loans/.
Wind and watertight vs practical completion: the difference for finance: common questions
Does wind and watertight mean a building is nearly finished?
No. Wind and watertight means only that the external envelope is sealed, so the roof is on, the windows are in and the external doors are hung, keeping the weather out while the interior is fitted out. The internal works, the services commissioning and all the certification still lie ahead. A building can look complete from the outside at wind and watertight and still be months of work away from practical completion.
Can I raise development exit finance at wind and watertight, before practical completion?
You can raise finance at wind and watertight, but it is not a clean exit bridge. It is closer to a finish-and-exit or part-complete facility, which funds the remaining works in stages and then bridges the sales period. Because works risk is still live, it prices above a completed-scheme exit bridge and advances less. We place these cases with lenders whose appetite fits part-built schemes, and any figure we quote is for illustration, never an offer of finance.
Why is finance at wind and watertight more expensive than an exit bridge at practical completion?
Because the lender is taking works risk. At wind and watertight the fit-out still has to be delivered and can run late or over budget, so the lender behaves more like a development lender: staged releases, a monitoring surveyor, and held-back leverage. At practical completion the works are done, the certificate confirms it, and the lender is only funding a sales period, so the pricing drops to an indicative 0.65 to 0.95 percent per month.
How does a valuer treat a wind and watertight scheme compared with a completed one?
At practical completion a RICS valuer reports the open market value of the finished units, which sets the gross development value the exit loan is sized against, so leverage can release in full. At wind and watertight the valuer usually reports the as-is value of the part-built asset and, separately, the GDV with the cost to complete deducted. A lender lends against the lower as-is figure and retains funds for the outstanding works.
What is the difference between wind and watertight and practical completion?
Wind and watertight is a construction stage where the external shell is weatherproof but the interior is unfinished and no certificate exists. Practical completion is a contractual milestone where the whole building is finished bar minor snags, a certificate is issued, retention is part-released and risk passes to the developer. The gap between the two is the internal fit-out and commissioning, plus the paperwork that proves the works are complete.
Is it better to switch off my development loan at wind and watertight or wait for PC?
It depends on the carry. Switching early clears the expensive development loan sooner but replaces it with dearer, lower-advance finish-and-exit funding. Waiting for practical completion secures the cheapest exit pricing and the highest leverage but means carrying the development loan for longer, with possible extension fees if it has matured. The decision is a straight comparison of extra carry now against cheaper money later, and we can model both on your scheme.
Does a wind and watertight certificate exist, like a practical completion certificate?
There is no formal, standardised wind and watertight certificate in the way there is a certificate of practical completion. Wind and watertight is usually confirmed by the monitoring surveyor or the contract programme as a drawdown or valuation milestone within a development facility, rather than by a certificate that passes risk or triggers retention. Practical completion, by contrast, is marked by a formal certificate issued by the architect, contract administrator or employer's agent.
What sign-offs does a lender want before it will fund a clean exit at practical completion?
A lender funding a completed-scheme exit typically wants the certificate of practical completion, sign-off from building control, a structural warranty like NHBC Buildmark on new homes, valid Energy Performance Certificates, and collateral warranties against the contractor and the design consultants. It will also want a RICS valuation of the finished scheme so the facility can be sized on gross development value, indicatively as much as 70 to 75 percent of GDV. Those figures are for illustration and are not an offer of finance.
Put this guide to work
Describe your scheme, the balance outstanding and the redemption date. Inside one working day you will know whether it funds and on roughly what terms.