Future purchase agreement for a new build

An objection we hear at almost every meeting: why sign a future purchase agreement (smlouva o smlouvě budoucí kupní) when it is not a purchase agreement (kupní smlouva) and I will not get the flat under it anyway? The answer is uncomfortable — with a new build (novostavba) still under construction there is no other way, and it is precisely this document that decides everything that happens over the following two years. This text goes through the future agreement article by article and ends with a checklist that compares what was in the listing (nabídka) with what is in the agreement.

Why you cannot sign a purchase agreement straight away for a new build

Until the owner’s declaration (prohlášení vlastníka) is registered, the unit (jednotka) does not legally exist. It has no number, no title deed (list vlastnictví), and there is nothing to transfer.

What remains, therefore, is an obligation to conclude the agreement later. Under § 1785 of Act No. 89/2012 Coll., the Civil Code (občanský zákoník), a party undertakes to conclude the future agreement “when called upon to do so within the agreed period, otherwise within one year”. The practical consequence: if no period is agreed, one year applies — with a project that takes two years to build, it expires before the building is completed. The agreed period is therefore not a formality but a condition without which the whole structure does not hold.

A second point follows from § 1786: the obligation to conclude the purchase agreement arises only after the other party has issued a call (výzva). Someone has to make that call — and the agreement should say who, in what form and to which address. The sentence “the parties will conclude the purchase agreement after occupancy approval (kolaudace)” does not resolve this.

In addition, in its judgment of 27 May 2022, case No. 33 Cdo 72/2021, the Supreme Court (Nejvyšší soud) concluded that a future purchase agreement concerning immovable property (nemovitá věc) does not have to be in writing. This changes nothing in the usual course of events, but it changes the reasoning about what was agreed: a promise made in the show flat (vzorový byt) can be binding — it is just very hard to prove. That is why everything that was said is written into an annex.

What a future purchase agreement contains when the flat does not yet exist

Instead of the thing itself, you are buying its description. What is not in the description you may not get, and any dispute is fought paper against paper.

The unit description should carry five details: designation and number, storey (podlaží), area with the method of measurement, share in the common parts (podíl na společných částech) and ancillary spaces (příslušenství) — cellar storage cage (sklepní kóje), parking space, terrace (terasa) — each with a specific number, not a count of items.

The rest is done by two annexes. Identified project documentation (projektová dokumentace): not “in accordance with the project documentation”, but the drawing number, stage, date and author exactly as they appear in the title block (popisové pole). A reference without identification points to a document that may be redrawn at any time. And the specification as a table (standard vybavení): item, manufacturer or parameter, quantity.

In the listings we handle, each unit has its own sheet with a dimensioned floor plan, its position on the storey plan and the drawing number in the title block. It is the only way the listing can be compared with the agreement line by line a year later.

Area and tolerance: this is where hundreds of thousands are decided

The average asking price (nabídková cena) of new flats in Prague in the second quarter of 2026 was CZK 182,700/m² (Deloitte Develop Index). At this price, every metre carries a weight that the tolerance in the agreement quietly redistributes.

A model flat of 68 m², i.e. roughly CZK 12,423,600:

• a tolerance of 2 % is 1.36 m², i.e. CZK 248,472;
• 3 % is 2.04 m², i.e. CZK 372,708;
• 5 % is 3.40 m², i.e. CZK 621,180.

The figure alone says nothing. What matters is how the tolerance works in both directions. The usual wording treats a deviation up to the agreed percentage as performance of the agreement — so a smaller flat is not refunded, whereas an excess upwards is charged extra. A symmetrical clause can be negotiated; someone just has to ask for it.

The second point is the method of measurement: under which standard the area is determined and what is included in it. The difference between floor area (podlahová plocha) including partition walls (příčka) and usable area (užitná plocha) is not negligible for the same flat.

Where square metres turn into tax

For large flats, the area has one more consequence. Under § 48a of the VAT Act (zákon o DPH), as amended with effect from 1 July 2025, the reduced value added tax rate of 12 % applies to residential space of up to 120 m² of floor area; above the threshold, 21 % applies. Under Decree No. 163/2025 Coll. (vyhláška), only rooms and spaces inside the perimeter structure of the building count towards the limit, so a balcony, a loggia or an outdoor terrace does not; according to the Financial Administration (Finanční správa), nor does a cellar storage cage outside the flat.

At a model price of CZK 20,000,000 excluding tax, the difference between the two rates is CZK 1,800,000. For a flat with a designed area just below the threshold, look in the agreement for a sentence on who bears the consequences of a change in the tax rate or in the legislation. A bare “the price includes VAT” shifts the risk to the buyer without saying so.

Deadline, penalties and the section that can cancel the agreement

The agreement usually contains three dates, and they get confused: the completion date of the building, the date for the call to conclude the purchase agreement, and the period within which the purchase agreement is to be concluded. The penalty is tied to the first of them, the one-year period under § 1785 to the third.

With penalties, read three things: the rate per day or week of default (prodlení), the cap and symmetry. A penalty capped at a very low percentage of the price is a gesture, not insurance. And if the buyer’s default carries a harsher penalty than the seller’s, that is a topic for negotiation, not a given.

Pay particular attention to § 1788(2): if circumstances change (změna okolností) to such an extent that the obligated party cannot reasonably be required to conclude the agreement, the obligation to conclude the future agreement lapses. The agreement can, however, define what the parties do not regard as such a change. Rising material prices, a subcontractor dropping out or extended proceedings at an authority belong to the builder’s (stavebník) risk, and it is sensible to say so explicitly. Without that, if the market turns unfavourable, the seller has an argument the buyer had no idea about until then.

Money that leaves before the flat exists

Instalments paid during construction go to the seller at a time when no registered unit stands against them — a lien (zástavní právo) on the unit arises only upon its entry in the Land Registry (katastr nemovitostí), under § 1316 of the Civil Code. Security is therefore assembled from several weaker elements.

• Tie instalments to a documented phase, not to a date, and state for each one how the phase is evidenced: an entry in the construction log (stavební deník), confirmation from technical supervision (technický dozor), a protocol.
• Pay the last part of the price only after the handover inspection (přejímka). A retained tenth is the only tool that still has an effect on a completed building.
• Deposit the balance in escrow (úschova) and have, in the list of documents against which the escrow agent (schovatel) releases payment, an extract from the title deed (výpis z listu vlastnictví) showing the buyer’s registered ownership right.
• Deal with the seller’s lien. On land under construction it is usually registered in Part C of the title deed, and that is a normal state of affairs. The agreement should contain the seller’s undertaking to ensure that the unit being transferred will be free of the lien at the moment the buyer’s ownership right is registered.

The future agreement is not entered in the Land Registry; until the unit exists, there is nothing to enter it against. Nor is a note (poznámka) on the unit after registration of the owner’s declaration an option: Act No. 256/2013 Coll., on the Land Registry (katastrální zákon), does not list the future agreement among registrations or notes (§ 11 and § 23). According to the Czech Office for Surveying, Mapping and Cadastre (Český úřad zeměměřický a katastrální, ČÚZK), the average time to complete registration (vklad do katastru) in August 2026 was 22 days nationwide, and registration may not be approved before the protective period (ochranná lhůta) of 20 days has elapsed (§ 18 of Act No. 256/2013 Coll.); this is covered in the text on the purchase agreement and registration in the Land Registry.

Assigning the agreement when you need to let the flat go early

Two years is a long time, and plans change. The only way to exit a future agreement without a loss is to assign it (postoupení smlouvy) to someone else; that person steps into your position with everything that belongs to it. Look for three details in the agreement: whether assignment is permitted, whether it requires the seller’s consent and whether a fee is charged for it. Agreements that prohibit assignment substantially reduce liquidity for an investment purchase.

Watch the tax side: assignment does not transfer immovable property but a contractual position, and the holding period test (časový test) for exempting income from the sale of property does not apply to such income (§ 4(1)(a) and (b) of Act No. 586/1992 Coll., on Income Taxes). The whole sequence of steps from reservation to handing over the keys is described in the text on buying a flat from a developer, step by step.

Where our own approach has a weak spot

We insist that the wording of the future agreement be an annex to the reservation (rezervace). We consider reserving a flat on terms nobody has seen to be a bad start. But it costs time: preparation takes longer, some prospective buyers go elsewhere in the meantime, and the developer does not like it. On fast-selling projects, this approach has cost us deals.

The second thing that is better said out loud: on projects where we represent the developer, we took part in drafting the future agreement. We cannot assess it impartially for the buyer, and we do not claim to. The checklist below compares the listing with the agreement, not the agreement with the law; the latter is a job for the buyer’s attorney (advokát).

Checklist: what to compare between the listing and the agreement

Print out the listing sheet (nabídkový list) with the floor plan and the draft agreement, and go through them in this order. Each item states where the detail is found in the listing and what must correspond to it in the agreement.

Unit

• Unit number and storey — title block of the listing sheet against the article on the subject of the agreement
• Area to one decimal place — sum of the dimensions in the floor plan against the figure in the agreement
• Method of measuring the area: the standard or methodology stated, not just the resulting figure
• Are the balcony, loggia, terrace and cellar storage cage counted in the area?
• The layout (dispozice), for example 5+kk (five rooms plus a kitchenette), matches the number and purpose of the rooms in the drawing
• Orientation (orientace ke světovým stranám) according to the storey plan

Ancillary spaces

• Parking space number and its marking on the garage plan, not “one parking space”
• Cellar storage cage number and method of transfer: part of the unit, or a share with exclusive use
• Terrace or front garden (předzahrádka): area and method of transfer
• Share in the common parts expressed as a fraction, not with the words “to be determined”

Price and payments

• Price in the listing against price in the agreement, both including tax and with the rate stated
• Are the parking space and the cellar storage cage included in the price, or charged separately?
• Who bears a change in the tax rate or a change in legislation
• Every instalment tied to a documented construction phase, not to a date — and how the phase is evidenced
• Last instalment due only after the handover inspection of the unit
• Balance into escrow, and a list of the documents against which it is released

Specification and client changes

• The specification table is an annex to the agreement and matches the one in the listing
• What from the show flat is in the specification and what is an extra — in writing
• Deadlines for client changes (klientská změna) by trade, not one general date
• Who prices the changes, and whether the price can be refused and the standard specification kept

Deadlines, penalties, security

• The date in the listing against the date to which the penalty in the agreement is tied
• The period for the call and for concluding the purchase agreement is agreed, not left to the law
• Penalty rates, their cap and symmetry between the parties
• Definition of what is not regarded as a change of circumstances under § 1788(2)
• Conditions for withdrawal (odstoupení od smlouvy) and what happens to instalments already paid
• Undertaking to hand over the unit free of any lien at the moment the buyer’s ownership is registered
• Whether assignment of the agreement is permitted and on what conditions

Annexes

• Project documentation identified by drawing number, stage and date
• Dimensioned floor plan of the unit, not a visualisation
• Payment schedule as a separate annex

Frequently asked questions

What is an SoSB for a new build? SoSB is the common abbreviation for smlouva o smlouvě budoucí, an agreement to conclude a future agreement. For a new build, it is the main document of the purchase: the purchase agreement signed a year or two later merely fulfils what is agreed here.

When is the future purchase agreement for a flat signed? As a rule after the reservation, at a time when the unit does not yet exist. It is sensible not to sign the reservation until the wording of the future agreement is attached to it as an annex.

Does a future agreement have to be made before a notary? No. In case No. 33 Cdo 72/2021, the Supreme Court concluded that for immovable property the law does not even require written form. Official verification of signatures (úřední ověření podpisu) only comes into play with the deed for the cadastral office (katastrální úřad): if the signatures are not verified, the applicant must prove their authenticity (§ 7(2) of Act No. 256/2013 Coll.).

What happens if the developer does not conclude the purchase agreement? Under § 1787(1), the entitled party can ask the court to determine the content of the future agreement. The court route is not fast, however — which is why penalties and withdrawal are negotiated in advance.

Can you withdraw from a future agreement? Only on the grounds stated in the agreement or on statutory grounds. With a long construction period, the article on withdrawal and on what happens to the instalments paid is the most valuable provision of the agreement.

Key takeaways

A future agreement is not a preparatory piece of paper; it is the main document of the purchase. It settles the unit description, the area tolerance, the tying of instalments to documented phases and the period that the law would otherwise set at one year. The cheapest moment for a change is the one before signing; after that, all that is left to negotiate with is goodwill. On the Prague projects we represent, we compare the listing with the agreement line by line.