Nairobians may have noticed a very large hole in the ground in the Upper Hill. It may be just a hole now but out of it will grow Nairobi’s two highest buildings, one of which will tower above the capital’s skyline to a height of 320 metres to become Africa’s highest building.

“The Pinnacle”, as the higher of the two buildings is to be called, is being built by Hass Petroleum and White Lotus, two Dubai-based investors who are sinking $220 million into the project. When completed, one of the sky-scrapers will consist of 150 ultra-smart apartments with a helipad on the roof, the other will be an up-market hotel.

For several years now, Nairobi’s skyline has been festooned with cranes working on new office blocks and new residential  developments are springing up everywhere as a building boom has gathered momentum – but will it last?

In recent times residential rents have fallen (6% down in 2016 according to the property firm Knight Frank) and some developments have come to a standstill.

The question is, how many Kenyans will be able to afford the rent in one of the new apartments, or stay at the hotel?

“The Pinnacle” could mark the high point in Nairobi’s building boom but some analysts fear it could also mark the start of the city’s building bust.