Inuua Case Study #1: Joe Ocholla - Rangau, Off Ongata Rongai Town

18 Sep 2020 at 7 p.m.

Kishan Bhanderi

Client Name: Joe Ocholla

Plot Location: Rangau, Off Ongata Rongai Town

Inuua Plan: ID 4231

Status: Ongoing, Ground Floor walling done. Preparing for 1st Floor Slab

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Inuua Maisonnette Plan ID: 4231

Mr Ocholla, visited our offices and bought his residential building plans in October 2019, after a short discussion.

Inuua’s Home Construction Architectural plans, come complete with Bills of Materials and all Engineering Drawings as well as access to online tools to manage the site.

As he prepared to start to build his home, he spoke to his supervisor (fundi) who suggested reducing the amount of Y8 re-bar from that shown in the Inuua Bill of Quantity and Materials.

After consultation, he felt the 8000/- saving on foundation by reducing this quantity was not significant in terms of the cost of building his home, and stayed with the Inuua design detail shown below.

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Y8 re-bar as designed on the Inuua Plan

He also considered using 32.5 grade cement vs 42.5 grade cement. 32.5 is slightly cheaper and more suited for plaster work vs 42.5 which is more for structure with greater strength.

The other thought he considered was the use of quarry dust which was more easily available nearby rather than river sand, for mixing with the cement.

Although, there are options for using this, one has to be very careful about the ratios mixed as it can affect the strength of the mix produced.

It is important to explore avenues to control costs when building a home, yet just as important to understand the consequences on quality of cost cutting decisions.

Mr Ocholla broke ground in January 2020, with excavation and foundation as shown in the images below.

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Foundation

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Foundation

There were some extra column bases added, on the fundi's recommendations, but an important crucial column had been omitted, which was corrected later.

At the end of March 2020, Mr Ocholla, having explored options, opted to complete his Ground Floor Slab using Ready Mix from Bamburi Cement.

The option meant his people had to do some preparatory work prior to arrival of the ready mix cement by truck, but the cement quality was high and consistent. In addition, this cement was poured in one morning.

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Ground floor slab work in progress

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Ground floor slab after

This meant there were no joins and the curing was also consistent resulting in a stronger slab.

Mixing on site by batch, has the possibility of being cheaper, but sometimes material waste and quality inconsistency, as well as time and labour costs need to be factored to determine overall value.

Mixing concrete

As Mr Ocholla prepared to do his Ground Floor walling, he opted for a clever solution, which was suitable for his area, as the stone quarry was nearby.

He got raw stone (not machine cut stone) delivered, and then hired a skilled labourer to ‘chonga’ (chisel) the stones.

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Manually chiselled blocks

This gave a decorative bush cut look for the outside and a smooth surface on the inside, saving him considerably on cladding the exterior and the costs to build his home! 👌

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As of 11th September 2020, Mr Ocholla was preparing to cast his first floor slab and staircase.

We shall update this post as Mr. Ocholla progresses. If you would like to get these updates plus many more, kindly subscribe to our newsletter at the bottom of this page.



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