The East African building boom continues apace — and artists are taking notice.

Elias Mung’ora is busily recording the changing face of Nairobi city centre while Jjuuko Hoods does the same for Kampala.

But theirs are urban landscapes in which the architecture becomes a backdrop to pavement chaos… the hawkers, shoppers, street kids and idlers — all players in the game of life.

Focusing instead on the buildings, and in particular half-completed office blocks and towers, are two other painters, both based in Nairobi: Sidney Mang’ong’o and Paul Njihia.

Both are still young (Mang’ong’o is 35 and Njihia 28) and so both presumably accept accelerated change as the natural order of things.

They salute it, revel in it and record it with unsparing eyes. Record it, but in Njihia’s case, not necessarily celebrate it.

Mang’ong’o delights in structure, showing us the play of light on plain walls and the abstract patterns found in ceilings and floors.

He also burrows beneath the skin of these half built towers to expose their internal skeleton of steel rods in collages, in which they beam like searchlights across the paper.

Njihia takes the opposite view. He is fascinated by the external scaffolding the workmen need; the buildings’ exo-skeletons, usually made of mangrove poles that form a rickety web on which the workers risk their lives.

What is missing is the skin… in this case the green safety mesh that clothes many of these new buildings, making them look as though they had been wrapped by the artists Christo and Jeanne-Claude.

Njihia omits it deliberately, strips it away to ensure the unstable scaffolding is at the heart of his paintings to highlight his belief that the safety of the workforce comes secondary to keeping costs low.

Paintings that work as a powerful polemic, therefore.

As the artist puts it: “These scaffolds are temporary structures for temporary people.”

Fourteen paintings making this point are on show until July 13 at the Nobo Gallery near Dagoretti Corner in Nairobi, in a gallery that adjoins the studio where he works with a group of other artists in a colony that is beginning to rival the city’s GoDown and Kuona Trust in the vitality of the work made there.

Of the 14, four small paintings are offered as one group and all ring the changes on the exo-skeleton and the dangers it poses.

All but one are painted in oils with a palette knife (mid-size with triangular blade, if like me you wondered) on pieces of unprimed plywood taken from packing cases, then further worked up with pastels.

The occasional irregularity of the boards adds to the rapid, instinctive feel of the works. In spite of the knife, the paint is generally thinly applied and on the best paintings (Residential II for instance) large areas of the board are left raw. It is as if the artist wants to tell us these structures are as transient as the men who build them.

The care with which the paintings have been made however indicates that they are finished works and not simply sketches for some future project.

Given Nairobi’s unfortunate history of building collapses, the paintings could indeed last longer than their subjects. Certainly most are more beautiful.

Outstanding to my eye is Njihia’s subtle use of colour… restrained but effective, it brings vitality to his work.

Njihia taught himself to draw and paint from “How-to” books and the internet. He also worked as a part-time caricaturist, which trained him to capture the essentials of a subject.

While in high school — the Light Academy in Nairobi — he often looked down from a balcony onto a car park and so began the series of paintings that brought him to notice — bird’s eye views of passers-by; first from life and later worked up from photographs.

But his current obsession is with the (financial) profit and (human) loss account of our new urban landscape; an obsession presented through drawings, his oils and pastels on plywood and, in a more formal and also more stilted manner, in oils brushed, not knifed, onto canvas.

There is only one of these in his Nobo show, called Finishing Touches, and, while more topographically accurate and the scaffolding more precise, it lacks the fiery spontaneity of his palette knife paintings.

For a self-taught artist his grasp of form is remarkably sound although it can slip from time to time. The perspective on the window bays fails in Planes, while both walls and windows look wonky in Untitled (No 2) and Untitled (No 11). Either the artist or the architect got things wrong.

Overall, however, this is an excellent exhibition and for sure the 14 paintings are greater than the sum of their parts. There is a momentum about them — both of the quality of his painting and of his argument — that makes a visit irresistible.

But what next?

I told Njihia I was curious to know how his theme would develop and what his next subjects might be.

He blanked me with the deadpan reply: “I am curious too.”