Energy Retrofit of an Existing Asset: Which Measures Pay and Which Do Not

Cooling dominates energy use in Saudi buildings. The retrofit measures worth paying for, the order to take them in, and the costs that appear once work starts.

In most Saudi buildings, cooling is the dominant energy cost, which means a retrofit that does not address heat gain or cooling efficiency will not move the bill. The measures worth taking are usually unglamorous: controls, envelope, lighting and plant, in roughly that order of cost effectiveness. This breakdown follows the lines an owner can act on and flags where the savings are real.

What this number does and does not include

This covers energy measures applied to an existing occupied or lettable building, from a measured baseline through implementation to verified savings. It excludes the original construction, any change of use, and the wider refurbishment work an owner may combine with it. No figures are given, because savings depend entirely on the existing building and its operating pattern, and any payback claim without a measured baseline is a sales pitch.

Measurement and the baseline

The cheapest line and the one that decides whether the rest is worth doing. Without a metered baseline broken down by system and time of day, you cannot identify where energy is going, prioritise measures, or prove a saving afterwards. Many buildings turn out to be running plant outside occupied hours.

• Pushes it up: Complex buildings with multiple tenants, no existing sub-metering and no operating records.
• Brings it down: Temporary logging rather than permanent metering for the assessment phase, focused on the largest loads.
• How to control it: Insist on a metered baseline with a breakdown by system before approving any measure, and use the same method to verify savings.

Controls and operating schedules

Almost always the best value measure. Plant running when the building is empty, setpoints that fight each other, simultaneous heating and cooling, and lighting left on all night are common and cost nothing to correct beyond commissioning time. The saving is immediate and requires no capital works.

• Pushes it up: Ageing control systems with no documentation, and tenants with individual control over shared plant.
• Brings it down: Recommissioning existing controls, correcting schedules and setpoints, and adding simple occupancy control where it is missing.
• How to control it: Carry out a controls audit and recommissioning exercise before considering any capital measure, then re-measure.

Cooling plant efficiency and sizing

The largest consumer in most buildings. Replacing plant with more efficient equipment produces real savings, and so does correcting oversizing, because plant that is too large cycles inefficiently. Replacement is capital-intensive, which is why it follows controls rather than preceding them.

• Pushes it up: Full plant replacement, difficult access for removal and installation, and continuity of service during the works.
• Brings it down: Replacing at the natural end of life, right-sizing rather than matching the old capacity, and staging replacement across plant items.
• How to control it: Reassess the cooling load after envelope and control measures, so the new plant is sized for the improved building rather than the old one.

Envelope: glazing, shading and insulation

Reduces the heat entering the building, which reduces the cooling needed permanently. External shading and glazing film or replacement on hot elevations usually outperform insulation upgrades in existing buildings, because glazing is where most of the gain arrives.

• Pushes it up: Glazing replacement, access equipment for upper floors, and work in occupied space.
• Brings it down: External shading and applied films rather than full replacement, and targeting only the elevations that receive the worst gain.
• How to control it: Prioritise elevations by measured solar gain, and treat the worst first rather than applying one measure everywhere.

Lighting and its cooling effect

Lighting replacement reduces both the lighting load and the heat it adds to the space, so the saving is larger than the lighting bill alone suggests. It is also straightforward to implement in stages and easy to verify.

• Pushes it up: Decorative or high-level fittings needing access equipment, and control system integration.
• Brings it down: Standard fitting replacement in bulk, with occupancy and daylight control in areas that are intermittently used.
• How to control it: Replace in areas with the longest operating hours first, and include the cooling saving when assessing the payback.

Water heating and pumping

Smaller than cooling in most buildings and often badly operated: hot water circulating all night, pumps running at full speed continuously, and storage temperatures higher than needed. Variable speed drives and schedule corrections are inexpensive relative to the saving.

• Pushes it up: Distributed systems across a large building and a lack of isolation valves for staged work.
• Brings it down: Variable speed drives on the largest pumps, schedule corrections, and insulating exposed distribution.
• How to control it: Log pump and hot water system operation for a week before specifying anything, because the operating pattern usually reveals the saving.

Verification and the rating question

Proving the saving with the same measurement method as the baseline, and deciding whether to pursue a recognised rating. A green building rating such as Mostadam can support letting and asset value, and it requires documentation and compliance work beyond the energy measures themselves.

• Pushes it up: Pursuing a rating on a building not designed for one, and gathering documentation retrospectively.
• Brings it down: Verification alone where the objective is operating cost, with a rating considered only if letting or value benefit is clear.
• How to control it: Decide the objective first, operating cost or marketability, and only pay for a rating process if the second is genuinely worth it.

Costs that never appear on the first page

• Working in an occupied building: out-of-hours labour, temporary services, protection and tenant coordination.
• Discovering that existing plant documentation is wrong, so the assessment has to be redone from survey rather than from records.
• Access equipment for upper-floor glazing and high-level lighting, which can rival the cost of the measure itself.
• Value added tax on works and professional services at the published headline rate of 15 per cent, with recovery depending on your structure. Confirm with ZATCA or a licensed adviser.
• Remedial work to asbestos or other hazardous materials found when plant or ceilings are opened up.
• Tenant compensation or rent concessions where works disrupt occupation, which is a real cost in a let building.

Keeping the budget honest

Spend on measurement first, controls second, and capital plant last. Recommissioning what you already have frequently delivers a meaningful reduction for the cost of an engineer week, and it also tells you what the capital measures should actually be. Never size replacement cooling plant before the envelope and control measures are done, because otherwise you buy capacity for a building that no longer exists.

• After the metered baseline is available, broken down by system and time of day.
• After controls recommissioning, with a re-measurement before any capital spend is approved.
• When elevations have been prioritised by measured solar gain rather than by appearance.
• Before cooling plant is specified, using a load recalculated for the improved building.
• At verification, comparing results against the baseline using the same method.

Domira designs, builds and manages projects across Saudi Arabia for owners who are based abroad: land appraisal, feasibility, design, construction, handover and asset management under one accountable contract. Send us the plot or the brief and Domira will put the numbers in front of you before you commit.