Unit mix: how the composition of units in a project is determined
Unit mix (bytový mix) is the ratio of layouts and areas in a single building — how many 1+kk (one room plus a kitchenette) and how many 2+kk (two rooms plus a kitchenette) units the project has, how large they are and how many square metres of the whole they take up. It is decided by the developer together with the architect over the floor plan at the design study (studie) stage, long before anyone opens the first price list (ceník). This text describes how the composition of units is put together, how it is checked and where mistakes are most often made.
The unit mix is an area budget, not a list of layouts
The composition is usually written down as counts: fifteen 1+kk, thirty 2+kk, ten 3+kk. It cannot be checked that way, because counts say nothing about how much saleable area (prodejní plocha) each group takes up.
A usable record has four columns: number of units, average floor area (podlahová plocha), total area and share of the total saleable area. Ten 4+kk units of 120 m² each make 1,200 m². With a total saleable area of 4,200 m², that is almost a third of the building handed to a group that accounts for a fraction of sales in Prague. In counts it looks like a sixth of the project, in metres like a third of it. The difference between those two views is the whole debate about the mix.
That is why we keep nine fields in the unit table (tabulka jednotek) — the sheet on which the project lives from the design study to the final sell-off: unit number (jednotka), storey (podlaží), layout, floor area, area of the balcony (balkon) or terrace (terasa), orientation, parking space number, cellar (sklep) number and price. The composition is not a separate document; it is a sum across this sheet. Once it appears in a file of its own, it parts ways with reality within a week.
Who decides on the composition and when the window closes
The developer decides, the architect proposes, and whoever is going to sell the project challenges. In practice the order is often reversed: the mix follows from the structural grid and from how many units fit on a storey, and the sales side sees it only when the documentation is finished.
The window for change closes when the permit application (žádost o povolení) is filed. After that, layouts can be changed only through new documentation, and that is a different discipline from rearranging rows in a table. What remains are the specification (standardy), the ancillary spaces (příslušenství) and the scope of client changes (klientská změna) — they decide how much freedom the project will offer, but they no longer change the flat size (velikost bytu). The whole sequence of stages from the design study to handing over the keys is described in selling a development project.
The mix has one more effect that is forgotten at the design stage. In the owner’s declaration (prohlášení vlastníka) — the document by which units come into existence in the building as objects of ownership — the share in the common parts (podíl na společných částech) is as a rule derived from the floor area of the unit. More small units mean more owners, smaller shares and a different distribution of votes in the future owners’ association (společenství vlastníků jednotek). Sixty-eight owners reach agreement on a roof repair differently from fifty-four.
Three inputs from which the composition is built
Achieved sales in the cadastral area (katastrální území). Not adverts (inzerát), but the prices at which flats in the area actually changed hands. An advert is the seller’s wish; a transaction is proof that a buyer exists for the given product at the given price.
Competitors’ remaining stock. What is left in the surrounding projects after two years of sales. The remainder is the most accurate map of mix mistakes that can be had for free — it shows exactly what the neighbourhood (čtvrť) has not absorbed.
Site plan and orientation. On the site plan (situace, the plan of the surroundings showing where the building sits) we mark two things: what can be seen from which unit and what can be heard from where. A north façade facing the inner courtyard of a block can carry a different layout from a south-west corner.
The first two inputs give the target share of layouts, the third their distribution across storeys. The same groundwork then also serves for the pricing of a development project, because the storey and orientation coefficients come from the same pencil on the site plan.
The Prague average does not sell. The neighbourhood and the price level do
In the first quarter of 2026, roughly 1,800 new flats were sold in Prague. 2+kk units made up roughly 45 % of them, 1+kk another 31 % — together more than three quarters of the market.
A quick and wrong conclusion can be drawn from this: let us build nothing but two-room flats. Yet roughly a third of all new flats sold were in Prague 9, and Prague 9 together with Prague 5 made up about half of the market. The Prague average is largely an average of a few development areas of the city. The composition of flats in a project in Vinohrady cannot be guided by it.
The difference between price levels is, moreover, greater than the difference between layouts. According to price maps from the first half of 2026, the level in Bubeneč was CZK 182,485/m² and in Prosek CZK 140,820/m²; in Třebonice, flats were offered in April 2026 at CZK 78,943/m². The same layout meets a different buyer with a different budget there. The table at the end of the text brings both axes together.
Model calculation: the same building, two mixes
A model apartment building (bytový dům) with 4,200 m² of saleable area in the middle price level. The building envelope, the number of storeys and the structure are identical in both variants; only the way the partition walls divide it differs.
Variant A, finer: 18 × 1+kk of 38 m², 30 × 2+kk of 55 m², 14 × 3+kk of 80 m², 6 × 4+kk of 124 m². In total 68 units and 4,198 m².
Variant B, coarser: 6 × 1+kk of 40 m², 18 × 2+kk of 58 m², 20 × 3+kk of 85 m², 10 × 4+kk of 122 m². In total 54 units and 4,204 m².
In the model we grade prices by unit size: 1+kk CZK 190,000/m², 2+kk 180,000, 3+kk 172,000, 4+kk 165,000. The spread between layouts is a model figure, distributed around the average sale price of a new build of CZK 177,647/m² for the first quarter of 2026.
Variant A: 684 m² × 190,000 + 1,650 m² × 180,000 + 1,120 m² × 172,000 + 744 m² × 165,000 = CZK 742,360,000, i.e. CZK 176,837/m².
Variant B: 240 m² × 190,000 + 1,044 m² × 180,000 + 1,700 m² × 172,000 + 1,220 m² × 165,000 = CZK 727,220,000, i.e. CZK 172,983/m².
The difference is CZK 15,140,000 on the same area and in the same building, i.e. 2.1 % of the volume. That is the whole answer to the question of why it pays to talk about the mix before talking about advertising.
The other side has to be written down right next to it. The finer variant means 14 more kitchens, bathrooms, front doors and flat distribution boards, and therefore a higher construction cost per metre. The statutory number of parking spaces (stání) in Prague, however, is calculated mainly from area: the basis is one space per 85 m² of gross floor area (hrubá podlažní plocha) of housing, at most two per unit, and the location within the city sets the minimum and the maximum from it. In both variants the result is therefore the same; more parking spaces and cellars will be demanded by the market, not by the regulations. And in a cooled market it means 68 buyers instead of 54. The difference of 15 million is gross revenue, not margin.
The metres inside a layout matter more than its name
2+kk is a range, not a quantity. A 2+kk unit of 42 m² and a 2+kk unit of 58 m² are two different products for two different buyers: the first sells as an investment flat for letting, the second as a replacement for an older 3+1 (three rooms plus a separate kitchen). In the price list they stand side by side under the same label, and in the report they are added up into a single row, which is the quietest mistake in the whole mix.
The control question for every row of the unit table is: is there a buyer in this neighbourhood whose budget covers this area times the price per metre? A 2+kk unit of 58 m² comes to CZK 10,584,130 at the Bubeneč level (58 × 182,485) and to CZK 8,167,560 at the Prosek level (58 × 140,820). The difference of CZK 2,416,570 decides whether it is an affordable unit or the upper edge of the band. For a new build both figures will tend to be higher, because the neighbourhood level also includes older flats.
Parking spaces, cellars and balconies are part of the mix, not an appendix
Ancillary spaces are designed together with the composition, not after it. The parking space number and the cellar number are fields in the unit table from day one, not an assignment added before signing. A unit without a parking space in the upper price band sells as a discount, whatever the price list says.
Ancillary spaces do not, moreover, work in the same way for all layouts. With a 1+kk, a balcony can decide whether the unit also appeals to someone other than an investor; large flats, according to the market analysis from May 2026, need clear added value, such as a terrace or a view.
How the mix is checked during sales
The monthly report is broken down by layout, not done as a total. Two columns stand side by side: the group’s share of the original offer and the same group’s share of what remains. As long as the two figures stay close together, the mix matches demand.
When the 2+kk units sell out in the first third of the sell-out period while the 4+kk units stand still, that is not a success but a diagnosis: the building has sold the layer that matched demand, and the rest will be sold off over the whole remaining time — at a price that will no longer go up. A deviation in one group that does not shrink from month to month is something we take as a signal to adjust the price list and the order in which units are released, not as a signal for a bigger advertising budget.
Where our approach has a weak spot
We usually push for a finer mix, because it sells faster and yields a higher price per metre. For a developer who calculates costs per unit, we thereby add kitchens, bathrooms, parking spaces and fourteen more contract processes. In a project with a thin margin the coarser variant may be the right one, and it must always be calculated by the cost estimator (rozpočtář), not by the salesperson.
The second weak spot lies in the data. We derive the composition from achieved sales that are several months old, while the project will be on sale in two years’ time. We look back and decide forward; for slow projects this is the greatest uncertainty of the whole method, and it cannot be removed, only admitted.
The third thing is more a matter of character than a fault: we will never design a mix according to the maximum number of units that fits into the envelope. For a developer who builds to sell metres rather than addresses, we are therefore a more expensive partner than we appear at the start.
Annex: demand for layouts by neighbourhood and price level
The price levels are medians of prices per m² from price maps for the first half of 2026; for the most expensive and the cheapest areas they are asking prices for April 2026. The other columns are our working estimate, not published statistics; the shares of layouts are model figures and show a direction, not a prescription for a particular building.
| Band | Example neighbourhoods and level | What sells fastest | Who buys | Model share 1+kk / 2+kk / 3+kk / 4+kk and larger (%) | What gets stuck in the band |
|---|---|---|---|---|---|
| Premium core | Josefov CZK 229,168/m², Malá Strana 219,110, Staré Město 206,899 | 3+kk over 90 m², large units with a terrace | Buyers with their own funds, second homes | 5 / 25 / 45 / 25 | Small units with no view and no parking space — at the band’s price level they cost as much as a 2+kk two neighbourhoods further out |
| Upper residential band | Bubeneč 182,485, Vinohrady 176,351, Karlín 174,584 | 2+kk 50–60 m², 3+kk up to 90 m² | Families buying an address, investors for long-term letting | 15 / 40 / 35 / 10 | 4+kk over 120 m² without a terrace and without a second parking space |
| Middle band | Holešovice 164,474, Dejvice 163,928, Smíchov 160,543, Strašnice 157,719 | 2+kk 48–58 m² | First own home, investors | 25 / 45 / 25 / 5 | Units over 100 m²; for the same price there is a 3+kk one neighbourhood up |
| Lower middle band | Žižkov 153,667, Nusle 152,945, Vršovice 152,078, Břevnov 151,127 | 1+kk 35–40 m² and 2+kk up to 55 m² | Investors, young buyers, a replacement for renting | 30 / 45 / 22 / 3 | Large layouts without a garden or terrace |
| Outer and housing-estate bands | Prosek 140,820, Újezd nad Lesy 112,221, Lipence 106,724, Třebonice 78,943 | 3+kk for families, 2+kk with a balcony and a parking space | Families with a reduced budget, few investors | 10 / 35 / 40 / 15 | A high share of 1+kk — rental demand is weaker and investors do not come here |
Two figures to go with the table. The Prague-wide share of 2+kk among new builds sold in the first quarter of 2026 was roughly 45 %, but roughly a third of all sales took place in Prague 9 — so the average is strongly pulled by a single city district (městská část). And a level of CZK 78,943/m² in Třebonice against CZK 229,168/m² in Josefov is a difference of 2.9 times: two different tasks, not two variants of one.
Frequently asked questions
Which layout sells fastest in Prague? According to sales of new flats in the first quarter of 2026, 2+kk units sold most, at roughly 45 %, followed by 1+kk at 31 %. In a particular neighbourhood, however, the order changes, and large flats are harder to sell mainly outside premium locations.
How many 1+kk units should a project have? That depends on the price level. The model table in the annex assumes 25–30 % in the middle and lower middle bands and 5 % in the premium core, because investment demand there works with a different price per metre.
Can the composition of units be changed after the permit has been issued? The layouts, practically speaking, cannot — that would mean new documentation and new proceedings. What can be changed is the specification, the ancillary spaces and the scope of client changes, i.e. what can be priced but not re-measured.
Why are small flats more expensive per metre? In a small unit, the cost of the bathroom, the kitchen and the entrance core is spread over a smaller area, and at the same time there are more buyers for it. The spread between layouts in the price list is not a surcharge but a reflection of both.
When should a developer discuss new-build layouts with the sales side? At the design study stage, i.e. before the detailed construction documentation (prováděcí dokumentace) is drawn up. Once the permit application has been filed, the debate about the composition is no longer about the product but about how to sell it as it is.
Key takeaways
The composition of units is an area budget and is measured in metres, not in numbers of flats. In the model calculation, two mixes in the same envelope differed by CZK 15,140,000 without a single load-bearing wall moving — and the same difference can just as well go the other way. The input is not adverts but achieved sales in the given neighbourhood and competitors’ remaining stock; the price level matters more than the Prague-wide average. And because the window for change closes when the permit application is filed, the debate about layouts is a question for the design study stage, not for the first week of sales.