Security documents are binding: good building practice is no defence

A common situation in a new housing company: the board notices something was done differently from the plans — tiles laid another way, a thinner insulation layer, a work step promised in the specification missing. The builder responds calmly: “Everything was built according to good building practice.” Many boards stop there. They shouldn’t — because if the build deviates from what was agreed, it may be a construction defect regardless of how carefully the work was done.

This is general guidance, not legal advice. Check your own building’s contracts and security documents, and consult a lawyer or a qualified expert if in doubt.

”As agreed” is the yardstick — and the security documents set the frame

In the sale of a new home, what was agreed is not just the text of the deed of sale. The essential facts about the project come from the security documents (turva-asiakirjat): the set of RS-system documents deposited with a keeper during construction and handed to the housing company. The basis is in chapter 2 of the Housing Transactions Act (843/1994), and the content is specified by a government decree.

The security documents include, among others, the main building drawings (pääpiirustukset) and the building method description (rakennustapaselostus) and special trade specifications (MEP, electrical, structural). It is precisely in these documents that the detailed specifications live — materials, surfaces, quality level and work steps according to which the project was promised to be built. What the security documents contain and what the housing company must obtain is set out here: Security documents: what the housing company must obtain.

The construction industry’s own guidance states the principle plainly: the project is carried out within the frame set by the security documents, and only to the extent the security documents do not mention something may the buyer assume it will be done with ordinary good building practice. In other words, good building practice complements what was agreed — it does not override it.

Deviating from what was agreed is its own, independent ground for a defect

This is the heart of the matter. The general defect provision in chapter 4, section 14 of the Housing Transactions Act lists several separate grounds, any one of which alone is enough to make a home defective. Under the section, a home has a defect if, among other things (translation of the Finnish text):

“1) it does not correspond to what can be considered agreed; — — 4) the construction — — has not been carried out in accordance with good building practice or in a professional and careful manner.”

Note that ground 1 (what was agreed) and ground 4 (good building practice) are different grounds. They do not cancel each other out. The fact that the work satisfies ground 4 — that it was done according to good building practice — does not cure a breach of ground 1 if the result does not match what was agreed. So the builder cannot invoke good building practice to defend a build that deviates from the security documents.

The builder’s claim	Why it is not enough on its own
”Built according to good building practice”	Good building practice is its own ground for a defect (ground 4) and complements what was agreed only where nothing was specified. Deviation from what was agreed (ground 1) is assessed separately.
”It meets the building regulations”	Regulations are a minimum (ground 2). If what was agreed required more, meeting the minimum does not remove the defect.
”The result works fine, though”	A defect is assessed against what was agreed, not against mere functionality.

When a detailed work step is left out

This is where a concrete dispute most often arises. The building method description or a special trade specification defines a particular work step, material or method — for example a specific seam sealant, insulation thickness, the layer thickness of waterproofing, or acoustic sealing. If this agreed step is left undone or replaced with another, the build deviates from what was agreed. The fact that the builder considers the result “in line with good building practice” does not change the situation: the agreed step is missing.

The principle: if a security document specifies how something is done, that specification binds. Good building practice fills the gaps — it does not grant permission to deviate from what was expressly agreed.

When good building practice is enough — and when it is not

In fairness, it is worth stating where the line runs. Good building practice is enough when the security documents take no position on a matter: if some detail was not specified, the builder may carry it out in the ordinary, good way, and that is not a defect. Good building practice is not enough when what was agreed says otherwise — there, what was agreed prevails.

One honest qualification: an insignificant deviation does not necessarily entitle you to remedies. Under general principles, a minor difference from what was agreed that does not affect the transaction or its terms does not yet give the buyer a right to make claims (this line is illustrated by KKO 2009:39, which concerns real-estate sale and applies here by analogy). What matters is whether the deviation has real significance — for living, cost, safety or the value of the property. A material deviation is worth pursuing; a wholly trivial one may not be.

How to prove the deviation: compare the build with what was agreed

A claim stands or falls on evidence. A deviation is shown by comparing the build against the security documents: the building method description, the special trade specifications and the main drawings. Here the as-built drawings (loppupiirustukset) are valuable — they show what was actually built, letting you demonstrate the gap against what was agreed in black and white. Note that as-built drawings are not the statutory, listed security documents themselves, but they are exactly the material with which a deviation is proven, so it is worth obtaining them.

In practice:

Find in the security documents the point that defines the agreed solution (the paragraph of the description, the detail on a drawing).
Document the actual situation with photographs, measurements and locations — see How to document a construction defect.
Compile these into one comparison: agreed vs. as-built. This is the backbone of the claim.

If needed, an independent building expert confirms the gap and its significance: When does a housing company need a building expert?.

Act in time — and remember the housing company can invoke the defect

A defect must be invoked in time. The most important checkpoint for a new project is the annual inspection (Housing Transactions Act 4:18, held 12–15 months after the occupancy approval), and a claim must be made within a reasonable time of when the defect was discovered or should have been discovered. A claim-based demand may become time-barred under the general limitation rules — typically about three years from when the basis was known — unless limitation is interrupted by a reminder or legal action. Read more: Claim to the builder and Warranty period and ten-year liability.

Important for the board: when the defect is in a part of the property that falls under the company’s maintenance responsibility, the housing company may have the right to invoke the defect instead of the buyer. Deviations in common areas and structures are therefore the board’s business — not an individual shareholder’s. If the builder stalls or denies, do not drop the item: When the construction company dodges its warranty liability.

Compare as-built against what was agreed in VAREK

“Good building practice” is not a magic phrase that erases a deviation from what was agreed. But proving it requires that the security documents are preserved and that the build can be compared against them. VAREK gathers the security documents and as-built drawings in one place, helps you record deviations as agreed–as-built pairs, and drafts a claim that rests on what was agreed — not on opinion.

This is general guidance, not legal advice. Assessing a defect depends on the project’s security documents, contracts and circumstances — confirm the details with a lawyer or a qualified expert if needed.

Frequently asked questions

Is it enough that the building was built according to good building practice?

No, if what was agreed required something else. Under chapter 4, section 14 of the Housing Transactions Act, deviating from what was agreed and failing to follow good building practice are separate, independent grounds for a defect. Good building practice is a minimum and default standard that applies only where the security documents are silent. It does not replace what was agreed.

Is the building method description binding?

The building method description (rakennustapaselostus) and the special trade specifications (MEP, electrical, structural) are among the security documents and form part of what can be considered agreed. The build must stay within the frame they set. A material deviation from the description can be a defect under the Housing Transactions Act, even if the work was otherwise done carefully.

Is every small deviation from the plans a defect?

Not necessarily. Under general principles, an insignificant deviation that does not affect the transaction or its terms does not entitle the buyer to remedies (cf. KKO 2009:39, which concerns real-estate sale and applies here by analogy). What matters is whether the deviation has real significance for living, cost or the value of the property.

Which documents do the security documents include?

Among others: the company's incorporation and registry documents, the financial plan, the property's title and encumbrance details, the building permit and main drawings, the building method description and special trade specifications, the construction contract and the collateral documents. The content is based on chapter 2 of the Housing Transactions Act and a complementary government decree.

Can the housing company invoke a defect, or only an individual buyer?

When the defect is in a part of the property that falls under the company's maintenance responsibility, the housing company may have the right to invoke the defect instead of the buyer. This matters precisely for defects in common areas and structures, for which the board is responsible.