What does one floor higher cost at Grand Tower?

The first question any buyer at Grand Tower asks is not what a square metre costs. It is what one floor higher costs. Normally that cannot be answered, because nobody sees the prices side by side.

For this building it can be. The developer's first-sale list of 26 May 2016 contains 195 units still available at that date, from the 1st to the 46th floor, with area, type and price per square metre. I received it as a buyer, and I have used it to calculate the price curve across the floors.

On method: what follows publishes no 2016 prices, only the shape of the curve as an index. The base of 100 is the median of the 1st floor, and every other figure is that floor's median relative to it. The list contained only the units unsold at that date, so it is a sample rather than a full census.

The price curve across the floors

Floor	Index (1st = 100)	Against previous step
1	100	base
5	114	+14%
10	113	level
15	120	+6%
20	122	+2%
25	126	+3%
30	136	+8%
31	161	+18%
35	162	level
39	170	+5%
41	174	+2%
42	178	+2%
43	271	+52%
45	302	+11%

Across the whole run from the 1st to the 42nd floor the price per square metre rises by roughly 78 per cent, an average of about 1.4 per cent per floor. That average is the least useful number in the table, because almost all of the increase sits in two steps.

The first threshold: floor 31

Between the 30th and the 31st the price jumps by about 18 per cent. That is the largest single step below the penthouses, and it happens within one floor.

Two things coincide there. The apartment types change, and the layouts of the upper half begin. And the sightline shifts: below that height the lower building stock stands in the picture, above it the stock sits underneath. The developer did not price this as a gradual climb but as a category of its own.

What actually changes at that threshold in daily life is set out in living above 150 metres and, for the sightline over the neighbouring tower, in the Spin notes.

The flat band: floors 31 to 42

Above the threshold the curve goes noticeably flat. Between the 31st and the 42nd the price rises by an average of only 0.9 per cent per floor, about ten per cent in total for eleven floors.

That is the most interesting stretch of the tower in pricing terms. Anyone buying in this band pays comparatively little for the additional height. Below the 31st, every floor costs more. Above the 42nd, every floor costs a multiple.

The second threshold: floor 43

From the 42nd to the 43rd the price per square metre jumps by about 52 per cent. That is where the penthouses begin.

The jump is not merely a premium, it is a change of product. The units from the 43rd upward are over 220 square metres, more than twice the size of a regular apartment, and on the topmost floors the index reaches roughly three times the 1st floor. The 42nd is already a transition floor on which the layout changes.

The change of product is not an improvement in every respect. In the units above my own floor, the smaller bedroom is proportioned such that a bed sits awkwardly in it. Buying more floor area does not automatically buy more usable area, and in the penthouse band most of the gain lands in the principal room.

That makes the 41st the last regular residential floor in the building: normal layout, normal ceiling height, normal size, with a different category starting above it. Whether the premium into that category makes sense is worked through in penthouse or 41st floor.

What the floor does not explain

One result of the analysis surprised me. On the 41st floor the corner units were priced only about 0.7 per cent above the other apartments on the same floor in the first sale. The developer, in other words, priced orientation and balcony size almost flat in 2016.

The resale market does not. An apartment currently offered on the 40th floor facing the Messe with a small balcony sits at roughly 12,650 euro per square metre. The unit one floor above it, with a skyline and south aspect and a large corner balcony, sits at roughly 13,470, about six per cent higher at practically identical height.

Put differently, the market has repriced since 2016 what the developer never priced in. Anyone comparing two offers in the building today should therefore treat floor, orientation and balcony type separately rather than netting them into one square-metre figure. The full price logic inside the building is set out in Grand Tower prices.

What this means for a buyer

Three things carry over from the curve:

• A floor number on its own says little. It only means something set against the building's full height. How that carries across to the other Frankfurt towers is set out in the tower price comparison.
• The thresholds matter more than the average. 1.4 per cent per floor is an arithmetic mean that exists nowhere in practice. What matters is the 31st and the 43rd.
• The band between 31 and 42 is the cheapest part of the tower. Height costs least per floor there.

The building overview sits in the Grand Tower guide, the building profile in Europa-Allee 2, and every post on the building in the Grand Tower hub. The apartment on the 41st floor sits on the 41st floor page; to look at it, reach me through the enquiry form on the home page.

External source: Grand Tower at skylineatlas.