Cost model: High-end apartment fit-out

A new series of cost models by Aecom begins with an indepth look at the costs of building services in high-end apartment blocks – this make up a considerable part of the central London construction market

Luxury apartment

In this cost model covering mechanical, electrical and public health services, Aecom examines the capital costs of installations for the fit-out of a typical high-end, two-bed apartment of around 800ft2, with en suite and family bathroom, and open-plan living area. The cost model features underfloor low temperature hot water heating, comfort cooling via two-pipe fan coil units, whole-house ventilation with heat recovery, lighting control and home automation

Background to the model

Demand for high-end apartments has become a significant component of the London construction market, with many properties sold ‘off plan’ years before the projects are completed. Although cost per square foot sales values are determined mostly by location in London, specification and offering must also be tailored to meet market needs and requirements, and the desire of the developer to provide a differentiator from the competition.

Purchasers are becoming more tech savvy and increasingly demanding not only the highest of quality, but also the ability to control the entire apartment from a smart device, whether they are in the country or not. This desire and increased knowledge of potential purchasers has resulted in the acceptable minimum standard increasing over a number of years.

In terms of audiovisual design and specification, how far do you go with technology that advances so quickly from year to year? The level of home automation required differs from one buyer to the next. There is definitely a push for fibre optics throughout to improve broadband performance, and this is a key consideration for many purchasers.

View from apartment. Caption: Shutterstock Yampi

The design of the heating and cooling systems needs to take into account overseas purchasers’ lifestyles. These properties may be left vacant for several months in a year, so boost functions should be designed into services for when the occupier returns.

In terms of sustainability, there has been a drive to place monitoring points on each of the services to measure consumption. Where the services are centralised, this is linked back to the service charge. Where the services are not centralised, however, there does not appear to be a need among many ultra-high net worth individuals to monitor consumption beyond payment of the bill. Installing these monitoring points adds to fit-out costs, but is not reflected in any enhancement to the sales premium. Sustainability measures are not high on the list of requirements with many prime purchasers, with the exception of those from the United States.

The sums included within this model are for subcontractors costs, testing and commissioning, preliminaries and overheads, and profit. The costs do not cover any main contractor additions or on costs.

Costs

Sanitaryware – Branded sanitary and brassware, includes an en suite with a bath, shower, WC, and his and hers wash hand basins, and a family bathroom containing a bath with shower over screen, WC and wash hand basin
£17.50/ft2 = £14,000 total

Soil and waste installations – Soil and waste to two kitchen sinks, dishwasher, washing machine and sanitaryware via plastic solvent welded pipework
£1.75/ft²= £1,400 total

Condensate installations – Condensate drainage from fan coil units and whole-house ventilation, via copper pipework, including discharge connections to the buildings infrastructure
£1.13/ft² = £900 total

Cold water installations – cold water pipework to sanitaryware and kitchen appliances via copper pipework
£2.50/ft² = £2,000 total

Hot water installations – Hot water pipework to sanitaryware and kitchen appliances via copper pipework with temperature maintenance. Local hot water storage provided to accommodate rain showers to bathrooms
£6.63/ft² = £5,300 total

Heat source – Plate heat exchangers for low temperature hot water and chilled water, with connections to shell and core services, complete with integral heat meters and insulated hood covers
£7.19/ft² = £5,750 total

Heating – Supplied by low temperature hot water underfloor heating throughout the apartment, complete with intuitive controls. Also includes electric towel rails to bathrooms £9.06/ft² = £7,250

Comfort cooling – two pipe fan coil units mounted in ceiling voids, complete with intuitive controls, providing cooling to living areas and bedrooms
£15.50/ft² = £12,400

Ventilation – Mechanical ventilation with heat recovery (MVHR) unit enabling whole-house ventilation with heat recovery and boost function, with an allowance for kitchen and bathroom extract discharging to building façade, including fans, ductwork, louvres and controls
£6.25/ft² = £5,000

Power – Includes consumer unit with meter to supply subsidiary circuits. Antique brass-finish, metal-faced sockets, cooker hobs, fused connection units, shaver outlets and kitchen grid plates, including wiring and installation to all of the above £5.63/ft² = £4,500

Lighting – To living areas and bedrooms supplied by LED downlighter, with bathrooms containing LED accent strip lighting and mirror light, complete with demister pads to complement downlighters. LED accent strip lighting is also within wardrobes. Costing includes all 5-amp lighting sockets, dimmable and non-dimmable metal-plate light switches, including wiring and installation to all of the above £26.75/ft² = £21,400 total

Lighting – scene set controls
£5.63/ft² = £4,500 total

Earthing and bonding £0.38/ft² = £300

Protective installation – Sprinklers throughout the apartment with connections to shell and core system, and monitored flow switch £2.81/ft² = £2,250

Fire alarm and leak detection – Includes smoke/heat detectors throughout and a leak-detection system, giving coverage of all wet areas £4.00/ft² = £3,200

AV/data, entry system and home automation – Includes antique brass-finish metal-face data and TV/satellite outlets. A full-colour touch-screen entry system and home automation system that includes blind control £12.50/ft² = £10,000 total

Total construction cost – Fit-out only
£125/ft² = £100,150 total CJ

Exclusions

1. Builders’ work in connection
2. Inflation beyond 4th quarter 2015
3. Main contractor’s on costs
4. Fees
5. VAT

About the authors
Garry Burdett, is a director of engineering services and Andrew Freeman is a trainee quantity surveyor, engineering services, both at Aecom