How Many Blocks and Bags of Cement Will It Take to Build a 4-Bedroom House in Kenya? Bills of Quantities and Bill of Materials

Building a 4-bedroom house in Kenya is a significant investment that requires meticulous planning, particularly when estimating the materials needed for construction. Cement and concrete blocks are critical components, forming the foundation, walls, and finishes of the structure. This article provides a detailed breakdown of the number of cement bags and hollow concrete blocks required to construct a single-storey, 4-bedroom house in Kenya with a Gross Floor Area (GFA) of 440 m². The estimates are based on a Bills of Quantities (BoQ) and Bill of Materials (BoM), derived from a comparable project in Namibia and adjusted for Kenya’s specifications, incorporating local material prices from reputable suppliers.

The number of blocks / bricks and bags of cement needed to build a house, depends on:
– the size of the house (the Gross Floor Area)
– the size of blocks or bricks used in the construction.

In this project, we estimate the quantities of all construction trades (Bills of Quantities) from Earthworks to Paintwork, as well as a Bill of Materials for the number of Wall Concrete Blocks and Bags of Cement required in this project. A case study of a newly completed 4-Bedroom Bungalow in Thika’s Ngoigwa Estate, Kiambu is used and estimated in this cost estimation.

Overview of the Project

The Kenya house is a single-storey, single-family residence with the following specifications:

Gross Floor Area: 440 m²
Features: 4 bedrooms, 4 bathrooms, parking for 4 cars
Total Estimated Cost: KSh 13,500,000

The cost and material estimates are based on a similar project in Namibia (435 m², N$ 1,615,470), adjusted using the method of equivalents and proportions to account for the slight difference in GFA (440 m² ÷ 435 m² = 1.0115 ratio). The Namibia project’s BoQ provides detailed quantities for concrete, plastering, and masonry, which are scaled to fit the Kenya house. Local Kenyan prices for cement and hollow concrete blocks are applied to create a realistic BoM.

Bills of Quantities (BoQ) Summary

The BoQ outlines the quantities and cost allocations for key construction categories, adjusted for the Kenya house’s 440 m² GFA. The total project cost of KSh 13,500,000 is distributed across categories based on the proportional cost breakdown from the Namibia project, with a subtotal of KSh 12,957,101 and contingencies of KSh 542,899 (4.19% of the subtotal). Below is the BoQ Summary Table for the Kenya House:

Description	Estimated Cost (KSh)	% of Subtotal
Preliminaries	412,741	3.19%
Earthworks	298,982	2.31%
Concrete, Formwork, and Reinforcement	940,356	7.26%
Masonry	1,698,664	13.11%
Waterproofing	27,210	0.21%
Roof Coverings	1,148,305	8.86%
Carpentry and Joinery	1,723,294	13.30%
Ceilings, Partitions, and Access Flooring	102,361	0.79%
Ironmongery	77,087	0.59%
Metalwork	467,757	3.61%
Plastering	605,097	4.67%
Tiling	770,927	5.95%
Plumbing and Drainage	348,459	2.69%
Glazing	62,890	0.49%
Paintwork	756,683	5.84%
External Works	1,342,356	10.36%
Provisional Sums	2,174,910	16.77%
Subtotal	12,957,101	100.00%
Contingencies	542,899	4.19%
Total	13,500,000	–

Detailed Quantities for Key Categories

Below are the specific quantities for concrete, plastering, and masonry, which directly inform the cement and block requirements:

Concrete, Formwork, and Reinforcement:

Strip Footings: 47 m³
Surface Beds on Waterproofing: 33 m³
Pavings: 11 m³
Ramps: 2 m³
Beams on Walls: 1 m³
Total Concrete Volume: 94 m³

Plastering:

25mm Thick Screeds: 335 m²
Internal Plaster:
- On walls: 1,242 m²
- On narrow widths: 13 m²
External Plaster:
- On walls: 862 m²
- On walls in foundations: 51 m²
- On narrow widths: 13 m²
Total Plastering Area: 2,516 m²

Masonry:

Brickwork in Foundations:
- Half brick (150mm thick, assumed internal): 80 m²
- One brick (200mm thick, assumed external): 115 m²
Brickwork in Superstructure:
- Half brick (150mm thick, assumed internal): 284 m²
- One brick (200mm thick, assumed external): 378 m²
- One brick in beamfilling (200mm thick): 22 m²
Total Masonry Area:
- External (200mm thick): 115 + 378 + 22 = 515 m²
- Internal (150mm thick): 80 + 284 = 364 m²

Material Prices in Kenya

To estimate costs, we use current market prices for materials in Kenya, sourced from reliable suppliers:

Simba Cement 32.5R (50kg bag): KSh 850.00 per bag (bulk purchase price for 220+ bags, as per Randtech Kenya).
Hollow Concrete Blocks:
- 200mm Wall Hollow Blocks (400 x 200 x 200 mm): KSh 90.00 per block (Construction Materials Kenya).
- 150mm Wall Hollow Blocks (400 x 150 x 200 mm): KSh 80.00 per block (Construction Materials Kenya).

Bill of Materials (BoM): Cement and Blocks

Using the BoQ quantities and standard construction consumption rates, we calculate the number of cement bags and hollow concrete blocks required. The assumptions are:

Cement for Concrete: 7.5 bags of 50kg cement per m³ (based on a 1:2:4 mix for general concrete works).
Cement for Plastering: 0.0225 bags of 50kg cement per m² (based on 25mm screeds and 12–15mm plaster).
Blocks per m²: 12.5 blocks/m² (based on block dimensions and standard 10mm mortar joints).

1. Cement for Concrete, Formwork, and Reinforcement

Concrete Volume: 94 m³
Cement Requirement: 94 m³ × 7.5 bags/m³ = 705 bags
Cost: 705 bags × KSh 850.00/bag = KSh 599,250.00

2. Cement for Plastering

Plastering Area: 2,516 m²
Cement Requirement: 2,516 m² × 0.0225 bags/m² = 56.61 ≈ 57 bags (rounded up)
Cost: 57 bags × KSh 850.00/bag = KSh 48,450.00

3. Total Cement for the Project

Concrete: 705 bags
Plastering: 57 bags
Total Cement: 705 + 57 = 762 bags
Total Cost: 762 bags × KSh 850.00/bag = KSh 647,700.00

4. Hollow Concrete Blocks for External Foundation Walls

Wall Area: 115 m² (one brick, 200mm thick)
Block Size: 400 x 200 x 200 mm
Blocks Required: 115 m² × 12.5 blocks/m² = 1,437.5 ≈ 1,438 blocks (rounded up)
Cost: 1,438 blocks × KSh 90.00/block = KSh 129,420.00

5. Hollow Concrete Blocks for Internal Foundation Walls

Wall Area: 80 m² (half brick, 150mm thick)
Block Size: 400 x 150 x 200 mm
Blocks Required: 80 m² × 12.5 blocks/m² = 1,000 blocks
Cost: 1,000 blocks × KSh 80.00/block = KSh 80,000.00

6. Hollow Concrete Blocks for External Superstructure Walls

Wall Area: 378 m² (one brick) + 22 m² (beamfilling) = 400 m² (200mm thick)
Block Size: 400 x 200 x 200 mm
Blocks Required: 400 m² × 12.5 blocks/m² = 5,000 blocks
Cost: 5,000 blocks × KSh 90.00/block = KSh 450,000.00

7. Hollow Concrete Blocks for Internal Superstructure Walls

Wall Area: 284 m² (half brick, 150mm thick)
Block Size: 400 x 150 x 200 mm
Blocks Required: 284 m² × 12.5 blocks/m² = 3,550 blocks
Cost: 3,550 blocks × KSh 80.00/block = KSh 284,000.00

Total Bill of Materials

Below is the summarized BoM for cement and hollow concrete blocks:

Item	Description	Quantity	Unit Price (KSh)	Total Cost (KSh)
Cement	Simba Cement 32.5R (50kg) for Concrete	705 bags	850.00	599,250.00
Cement	Simba Cement 32.5R (50kg) for Plastering	57 bags	850.00	48,450.00
Subtotal Cement	Total for Project	762 bags	850.00	647,700.00
Hollow Blocks	200mm (400 x 200 x 200 mm) for External Foundation Walls	1,438 blocks	90.00	129,420.00
Hollow Blocks	150mm (400 x 150 x 200 mm) for Internal Foundation Walls	1,000 blocks	80.00	80,000.00
Hollow Blocks	200mm (400 x 200 x 200 mm) for External Superstructure Walls	5,000 blocks	90.00	450,000.00
Hollow Blocks	150mm (400 x 150 x 200 mm) for Internal Superstructure Walls	3,550 blocks	80.00	284,000.00
Subtotal Blocks	Total for Project	10,988 blocks	–	943,420.00
Total Material Cost	–	–	–	1,591,120.00

Cost Context Within the Project

The total material cost for cement and blocks (KSh 1,591,120) represents approximately 11.8% of the overall project cost of KSh 13,500,000. The BoQ cost breakdown shows that masonry (KSh 1,698,664) and concrete (KSh 940,356) are significant cost drivers, with plastering (KSh 605,097) also contributing. These categories include additional materials (e.g., sand, gravel, reinforcement bars) and labor costs not covered in the BoM. The contingencies (KSh 542,899, or 4.19% of the subtotal) provide a buffer for unforeseen expenses.

Key Considerations

Cement Consumption: The estimates assume a 1:2:4 concrete mix (7.5 bags/m³) and typical plastering mixes (0.0225 bags/m²). Local practices or specific mix designs may vary, so consult with a local contractor for precision.
Block Selection: Hollow concrete blocks (200mm for external walls, 150mm for internal walls) are chosen for their cost-effectiveness and reduced mortar requirements (5mm joints vs. traditional 200mm). These blocks comply with Kenyan standards (KS 02-625) for load-bearing and non-load-bearing applications.
Additional Features: The Kenya house includes 4 bathrooms and parking for 4 cars, which may slightly increase quantities for plumbing and external works (e.g., paving). These are accounted for in the adjusted BoQ but not directly in the cement and block calculations.
Cost Savings: Hollow blocks reduce cement and sand usage in mortar and plastering, making them a cost-effective choice compared to solid blocks or machine-cut stones.
Sourcing Materials: Prices are sourced from reputable suppliers like Randtech Kenya and Construction Materials Kenya. Bulk purchasing (e.g., 220+ cement bags) ensures the lowest unit costs.

Tips for Homebuilders in Kenya

Verify Quantities: Work with a qualified quantity surveyor to confirm quantities based on your specific house design, as variations in layout (e.g., open-plan vs. partitioned) can affect block and cement needs.
Negotiate Bulk Discounts: The cement price of KSh 850.00 per bag assumes a bulk purchase. Contact suppliers like Randtech or Kisumu Concrete Products for potential further discounts.
Quality Control: Ensure blocks meet Kenyan standards (e.g., 2.8–7 N/mm² compressive strength) and cement is suitable for structural applications (e.g., Simba 32.5R).
Logistics: Factor in delivery costs, especially for a large quantity of blocks (10,988 units). Suppliers like Kisumu Concrete Products offer direct delivery to job sites.
Contingencies: The project includes a 4.19% contingency (KSh 542,899) to cover unexpected costs. Keep a buffer for material price fluctuations or design changes.

Conclusion

Building a 4-bedroom, single-storey house in Kenya with a 440 m² GFA requires approximately 762 bags of 50kg Simba cement (705 for concrete, 57 for plastering) and 10,988 hollow concrete blocks (6,438 of 200mm for external walls, 4,550 of 150mm for internal walls). The total cost for these materials is KSh 1,591,120, based on bulk prices of KSh 850.00 per cement bag and KSh 90.00/80.00 per 200mm/150mm block. The BoQ Summary Table provides a comprehensive view of the project’s cost distribution, ensuring transparency in budgeting. These estimates, derived from a proportional adjustment of a Namibian BoQ, offer a solid foundation for planning. For precise estimates, consult a local quantity surveyor and verify material requirements with your architect or contractor.

For further details or a downloadable BoM/BoQ in Excel/Word format, contact a construction professional or use online tools to refine your project plan. Happy building!

Sources

Bills of Quantities data adapted from a Namibian project (435 m², N$ 1,615,470).
Cement prices: Randtech Kenya.
Block prices: Construction Materials Kenya.
Additional supplier data: Kisumu Concrete Products.

Note: Material prices are subject to change. Verify current rates with suppliers before finalizing your budget. If you need a formatted table or additional material estimates (e.g., sand, gravel), let me know!

4 Bedroom House for Sale in Thika, Kiambu

Cost Comparison Analysis of 4-Bedroom Houses in Kiambu and Nairobi

The real estate market in Kenya is defined by sharp contrasts between suburban affordability and city luxury. Nowhere is this more evident than in the Kiambu Region versus the Nairobi suburbs, where 4-bedroom houses dominate demand among families, professionals, and investors. This article examines a new 4-bedroom bungalow in Thika as a case study, comparing it to similar properties in Ruiru, Runda, Loresho, and Lower Kabete to highlight regional price variations, project scope, and class distinctions.

A Case Study: The Thika 4-Bedroom Bungalow

In Thika’s Ngoigwa Estate, a modern bungalow is on the market for KSh 13.5 million. Built on a standard 50 × 100 ft plot (0.13 acres), the house offers a 440 m² floor area—a significant size compared to most suburban houses. All four bedrooms are ensuite, complemented by a spacious kitchen, sitting room, and parking for up to four cars. The property is pet-friendly, comes with a small garden, and lies just 100 meters from Thika Road and 1.5 kilometers from Thika CBD.

At KSh 30,681 per m², this home represents the upper-middle-class market in Kiambu. It provides indoor space and comfort at a price point that balances accessibility with quality. While it lacks the expansive lawns and estate branding seen in Nairobi’s luxury suburbs, it offers functionality, security, and affordability in a fast-growing satellite town.

Kiambu Region Comparisons

The Kiambu housing market is diverse, ranging from modest bungalows to high-end maisonettes. Compared to the Thika bungalow, Ruiru presents more premium alternatives:

4-bedroom maisonette in Ruiru (KSh 19 million) — offers 230 m² of floor space. Although smaller inside, it sits in a more prestigious gated estate with manicured gardens, high-quality finishes, and parking for up to five cars. Its price per m² (KSh 82,609) is nearly three times that of the Thika bungalow, reflecting both location and finish quality.
Executive Ruiru home (KSh 28 million) — features 465 m² floor area on a similar 50 × 100 ft plot. With balconies, ample parking, and luxury finishes, it caters to the upper-class buyer in Kiambu. Its price per m² (KSh 60,215) sits between the Thika and Nairobi benchmarks, offering a blend of space and prestige without city-level costs.

Key Insight: In Kiambu, buyers pay a premium in Ruiru for proximity to Nairobi, estate branding, and lifestyle amenities, while Thika offers more floor space for less money, appealing to families seeking value.

Nairobi Region Comparisons

Crossing into Nairobi, the market transforms dramatically. Properties here reflect exclusivity, expansive plots, and world-class finishes:

Runda — a 4-bedroom villa on half an acre is priced at KSh 85 million. With a 450 m² floor size, its price per m² is KSh 188,888—over six times the Thika rate. Buyers here pay not just for space, but for the prestige of an address synonymous with Nairobi’s elite.
Loresho and Lower Kabete — executive homes range between KSh 105 million and KSh 109 million for roughly 400 m². These command an astonishing KSh 262,500 per m², positioning them in Nairobi’s luxury upper-class bracket. Their selling points include landscaped gardens, top-tier finishes, and the status of living in one of the capital’s most exclusive neighborhoods.

Key Insight: Nairobi homes cost 6–10 times more per square meter than Kiambu equivalents, reflecting the combined influence of location, land value, and prestige.

Comparative Overview

Location & Type	Price (KSh)	Floor Size (m²)	Price per m²	Plot Size	Market Class
Thika Bungalow	13.5M	440	30,681	0.13 ac	Upper-Middle
Ruiru Maisonette	19M	230	82,609	0.12 ac	Upper-Middle / Entry Luxury
Ruiru Executive Home	28M	465	60,215	0.12 ac	Upper Class (Kiambu)
Runda Villa	85M	450	188,888	0.5 ac	Upper Class (Nairobi)
Loresho / Kabete Villas	105M–109M	400	262,500	0.12–0.5 ac	Luxury Upper Class

Final Verdict

The Thika bungalow at KSh 13.5 million represents an affordable upper-middle-class option, offering large floor space at a fraction of Nairobi prices. Buyers in Kiambu can secure more square meters per shilling, though with less prestige and outdoor luxury. Ruiru’s maisonettes and executive homes bridge the gap, offering proximity to Nairobi with mid-level luxury.

In contrast, Nairobi’s prime estates—Runda, Loresho, Lower Kabete—remain firmly in the upper-class luxury tier, where buyers prioritize exclusivity, land size, and status over cost efficiency.

For homebuyers and investors, the choice depends on priorities: