BIM and sustainable building design: what owners and project teams should know

Construction projects have long suffered from the same problems: services that clash in ceiling spaces and have to be ripped out and reinstalled, quantities that differ between drawings, design changes that are not carried through every document, and owners who receive boxes of drawings and manuals they cannot use to run the building. Meanwhile, buildings designed to be efficient often use far more energy than predicted, because performance was treated as a feature to add late rather than a goal to design for from the start.

Building information modelling, or BIM, addresses both problems when it is used well. It replaces separate drawings with coordinated digital models containing geometry and information, shared by the design and construction team, so conflicts are found on screen rather than on site, quantities come from one source and design options can be analysed for energy, daylight and cost. At the end, the owner can receive structured information about every asset in the building. Used poorly, BIM produces impressive models that nobody coordinates, information nobody asked for, and handover files the owner cannot open.

This article explains what BIM is, how information is planned and managed, the practical benefits for coordination and construction, how BIM supports sustainable design and performance analysis, what owners should ask for at handover, and how to close the gap between predicted and actual performance. It is general information for building owners, developers, project managers, designers and contractors.

What BIM is

BIM is a process for creating and managing information about a building throughout its life, using shared digital models. A BIM model is not just a 3D drawing. Each element, such as a wall, door, duct or pump, is an object with properties: its type, dimensions, materials, performance, manufacturer and maintenance requirements. Drawings, schedules and quantities are generated from the model, so a change made once appears everywhere.

People sometimes describe further “dimensions” of BIM: linking models to time for construction sequencing, to cost for estimating, to sustainability for performance analysis and to operations for facilities management. The terms vary, but the idea is the same: one structured body of information used for many purposes.

Planning and managing information

BIM succeeds when information is planned. The international ISO 19650 series sets out principles for managing information over a building’s life using BIM. Key ideas include:

Information requirements: the owner states what information it needs, when and in what form, for decisions during the project and for operating the building afterwards.
A BIM execution plan: the delivery team sets out how it will meet those requirements, including responsibilities, software, standards, model structure and coordination processes.
Level of development: how detailed and reliable each element’s geometry and information must be at each stage. Over-modelling early wastes effort; under-modelling later leaves gaps.
A common data environment: a shared, controlled repository for models and documents, with status codes such as work in progress, shared, published and archived.
Open formats: Industry Foundation Classes, an open standard, allow models to be exchanged between different software, which matters when designers, contractors and owners use different tools.

The most common BIM failure is not technical. It is starting modelling without agreeing what information is needed, by whom and why.

Coordination and construction benefits

Clash detection combines architectural, structural and services models and automatically finds conflicts, such as a duct running through a beam or a pipe and a cable tray in the same space. Coordination meetings resolve them before construction, avoiding rework, delays and variations.

Other benefits include:

Quantity take-off from the model for estimating and procurement.
Visualisation that helps clients, users and approvers understand the design.
Construction sequencing and logistics planning, by linking model elements to the program.
Prefabrication, where accurate models support off-site manufacture of services modules, frames and components.
Change management, because the effect of a change can be seen across the whole model.

These benefits depend on discipline: consistent modelling standards, regular coordination cycles, clear responsibility for resolving clashes and a single current version of each model. Clash reports also need judgement: automated checks find many trivial or duplicate clashes, so teams set tolerances and rules, group related clashes and focus coordination time on the conflicts that would genuinely cause rework on site.

Designing for sustainable performance

Sustainable design is most effective when it starts early, when decisions about form, orientation and envelope cost little to change and have the greatest effect. A practical sequence:

Understand the climate and site: temperatures, humidity, sun paths, prevailing winds, rainfall, shading from neighbours and site constraints.
Set performance targets: energy, water, comfort, daylight, embodied carbon and any rating targets.
Reduce demand first, the most important step:
- Orientation: in Australia, as in the rest of the southern hemisphere, north-facing glazing receives winter sun and is easily shaded from high summer sun with horizontal shading. East and especially west glazing receive low-angle sun that is hard to shade and drives summer cooling loads.
- Massing and form: compact forms reduce surface area and heat exchange; narrow plans improve daylight and natural ventilation.
- Envelope: insulation, airtightness and thermal bridging matter as much as equipment efficiency.
- Glazing: the right amount, in the right places, with suitable performance; more glass is not better.
- External shading: stops heat before it enters, unlike internal blinds.
Use daylight and natural ventilation where the climate and use allow.
Choose efficient systems, sized for the reduced loads.
Add on-site renewables, such as solar panels, once demand has been reduced.
Manage water with efficient fixtures, rainwater harvesting and water-sensitive landscaping.
Select materials for durability, lower embodied carbon, recycled content and healthy indoor air.

Each unit of demand removed early shrinks the mechanical and renewable systems needed, lowering capital and running costs and improving resilience.

Analysis with BIM

BIM models can feed energy modelling, daylight analysis, solar studies and computational airflow analysis, allowing design options to be compared early. Results depend on inputs such as weather data, occupancy, equipment loads and operating schedules, so analysis should be done by competent people, with assumptions recorded and results treated as comparisons between options rather than precise predictions. The choosing a 3D model that suits the design question article explains matching model detail to the question being asked.

Rating tools and regulation

In Australia, the National Construction Code sets minimum energy efficiency requirements, including Section J for commercial buildings. Voluntary rating tools include Green Star, which rates the sustainability of buildings and communities, and NABERS, which rates the measured operational performance of existing buildings for energy, water, waste and indoor environment. Residential buildings commonly use NatHERS for thermal performance. Choose targets that suit the project’s purpose and market, and remember that measured operational ratings, rather than design intentions, show what a building really achieves.

Embodied carbon

Operational energy is only part of a building’s climate impact. Embodied carbon, the emissions from producing, transporting and installing materials and from eventual demolition, can be a large share of the total, especially in efficient buildings. Concrete, steel, aluminium and glass usually dominate. Options include using less material through efficient structural design, specifying lower-carbon concrete mixes and recycled steel, choosing timber or other lower-carbon systems where suitable, designing for long life and adaptability, and reusing existing buildings rather than demolishing them. Model quantities make it easier to estimate embodied carbon and compare options early.

The performance gap

Many buildings use substantially more energy in operation than design models predicted. Common reasons include changes during design and construction that were not reflected in analysis, systems installed or commissioned poorly, controls never tuned, occupants using the building differently from assumptions and maintenance that lets efficiency decline.

Closing the gap requires:

Keeping analysis updated as the design changes.
Thorough commissioning, testing that systems work as designed under real conditions.
Seasonal tuning in the first year of operation.
Metering and monitoring of energy and water by system, compared with targets.
Feedback from operations into future designs.

The cutting energy use in business premises article covers ongoing energy management in occupied buildings.

What owners should ask for

Owners gain most from BIM when they define their needs early:

Decide what the model is for after handover: space management, maintenance planning, asset registers, future refurbishment.
Specify the asset information required, such as equipment types, serial numbers, warranties, maintenance requirements and locations, and the format, which may be a structured data exchange that can be loaded into maintenance software.
Require as-built accuracy, verified before handover, rather than design models with construction changes missing.
Specify open formats and ownership rights, so the owner can use the information without depending on one software vendor or consultant.
Plan who will maintain the information after handover, or it will quickly become outdated.
Test a sample of the handover data in the maintenance system before final acceptance, so gaps are fixed while the delivery team is still engaged.

The preparing CAD files for a reliable handover article covers the practical side of handing over digital design information.

Contracts and responsibilities

BIM changes how design information is shared, so contracts need to keep up. Agree which models are contractual documents and which are for information only, how model status is shown, who owns the models and who may use them for what, how liability works when one party relies on another’s model, and how model information interacts with drawings and specifications if they conflict. Without these agreements, disputes about responsibility for errors and changes become harder to resolve.

BIM on smaller projects

BIM is not only for large projects. On smaller buildings and fit-outs, the same principles apply at a smaller scale: a coordinated model of the tight services zones, quantities for estimating, a simple asset list for the owner and early checks of orientation and shading. The key is proportion: decide which uses of BIM will pay on this project, and model to that level, rather than adopting every capability by default.

A worked example

This is an illustrative example. A developer is building a three-storey medical centre with consulting rooms, a small day surgery and retail on the ground floor. The developer’s facilities team will run the building, so it sets information requirements at the start: a coordinated model for construction, energy and daylight analysis at concept stage, and an asset register for all mechanical, electrical and hydraulic equipment at handover.

Design. Early massing studies compare three options. The chosen design places most glazing on the north facade with horizontal shading, reduces west-facing glass and uses external vertical fins on the east. Energy modelling of the options shows the chosen design reduces the modelled peak cooling load by about 18% compared with the original concept, allowing smaller chillers and air handlers.

Coordination. Fortnightly coordination combines the architectural, structural and services models. Over the design period, about 140 clashes are found and resolved, most between ducts, pipes, cable trays and structural beams in the congested ceiling spaces above the day surgery. Services are partly prefabricated from the coordinated model.

Handover. The contractor updates the model to as-built condition, verified by spot checks, and delivers the asset register in a structured format loaded into the facilities team’s maintenance system. Commissioning and a year of seasonal tuning follow, with energy use tracked against the model.

Result. Services rework during construction is minimal, the facilities team starts operations with complete asset data, and first-year energy use is close to the adjusted model prediction after tuning.

Applying this in an Australian business

Define information requirements before modelling starts.
Agree a BIM execution plan, common data environment and level of development.
Use clash detection with regular coordination cycles.
Design for performance early, reducing demand before adding technology.
Orient glazing to the north and control east and west sun.
Treat analysis as comparison, with recorded assumptions.
Commission, tune and meter to close the performance gap.
Specify useful handover data in open formats.

Where BIM and sustainable design go wrong

Modelling without agreed information requirements.
Models that are never coordinated.
Sustainability features added late instead of designed in.
Northern hemisphere design rules applied to Australian buildings.
Energy models treated as guarantees.
Poor commissioning and untuned controls.
Handover data the owner cannot use.
Clash reports generated but never worked through to resolution.
Renewables added before demand has been reduced.

Questions to ask on a building project

What information do we need from the model, during the project and afterwards?
Who is responsible for coordinating models and resolving clashes?
What performance targets have we set, and when were they tested?
How have orientation, shading and envelope been optimised?
How will commissioning and first-year tuning be done?
In what format will we receive asset information, and who will maintain it?

Bringing it together

BIM turns building design and construction into a coordinated information process. Planned well, it finds conflicts before they reach site, supports quantities, sequencing and prefabrication, and hands owners usable asset information. Combined with early, climate-appropriate sustainable design, reducing demand through orientation, form, envelope, glazing and shading before adding systems and renewables, it helps deliver buildings that perform as intended. Closing the gap between prediction and reality needs commissioning, tuning and measurement. The result is fewer surprises during construction and lower costs for decades afterwards.

Source: KEVOS editorial notes, drawing on earlier KEVOS study material on building information modelling, BIM authoring workflows, green BIM for sustainable design and performance analysis and green building design, together with established building design practice. The worked example is illustrative. This article is general information.