RENOVATIONS AND ADDITIONS
With careful planning, thoughtful design and a considered choice of builder, renovations and additions can improve the liveability and sustainability of your home or work space.
Here’s some information to help you understand the crucial elements to consider when renovating. We work with you and your budget to address as many of them as possible.
Most local governments have planning policies that allow minor internal and external changes that don’t alter the structure or services to be made without Council approval, but it’s always best to check first. Alterations to services (e.g. plumbing, drainage, gas and electrical) do require approval and inspection by the relevant authority but may not require planning or building approval.
Many publications have advice on home renovation (see ‘The information here focuses on those aspects of renovation that improve the environmental performance of your home.
Improving thermal comfort
The options below for improving thermal performance while renovating are described in more detail in ‘Passive solar heating’, ‘Passive cooling’ and the specific articles noted.
Windows and glazing
- Replace windows or glazing with high performance units appropriate to the climate or consider retrofitting double glazing to serviceable timber windows that you plan to keep (see ‘Design for climate’ and ‘Glazing’).
- Improve air seals as you refit sashes (see ‘Sealing your home’).
- Use polycarbonate films with magnetic attachments to emulate double glazing during winter.
- In locations where you want to increase exposed thermal mass, remove the carpet or other insulative coverings on slabs and replace them with tiles or polished concrete finishes. Information from building sustainability assessors indicates that, in many climates, this can raisethe Nationwide House Energy Rating Scheme (NatHERS) ratings by up to one star (see ‘Thermal mass’).
Ventilation, air movement and draughts
- Improve cross-ventilation by:
- retrofitting fully openable, breeze-catching windows and doors
- creating new openings in non-loadbearing walls and above doors
- moving doors to improve breeze paths
- designing landscaping planting, outbuildings or fences to direct breezes through the home
- removing planting that blocks breeze access, unless needed as a windbreak.
- Install ceiling fans or whole-house fans (see ‘Passive cooling’).
- Replace halogen downlights with low-energy models, seal the openings and replace the insulation over them. Electrical retail outlets can supply sealed, heatproof boxes for downlights that seal them and allow you to insulate over them without fire risk.
- Add insulation to accessible floor, wall and roof sections (it can be easily removed and reused later if these sections are demolished).
Improving energy efficiency
- Consider installing an active solar heating system, particularly if your home has no solar access to north-facing glass (see ‘Heating and cooling’).
- Upgrade your heating and cooling system with one that:
- has the highest energy star rating you can afford
- only heats or cools rooms that are in use.
Improving water efficiency
- Retrofit the highestWater Efficiency Labelling and Standards (WELS) star-rated toilets, showers and taps available (see ‘Reducing water demand’).
- Install flow restrictors on taps that deliver too much water (e.g. handbasins, sinks).
- Install rainwater tanks (some councils require approval over a certain size, so check first).
Improving indoor air quality
- Ensure high levels of controllable natural ventilation or fans in rooms that are difficult to ventilate.
- Consider heat recovery ventilation systems in cooler climates (see ‘Sealing your home’).
- Neutralise outgassing paints and finishes already in the home with specialised sealants (see ‘The healthy home’).
Improving space and amenit
To reduce new construction:
- Build or improve outdoor living spaces close to kitchen and indoor living areas. In particular, consider summer shade, insect proofing and winter sun.
- Install additional, purpose-built
- Consider relocating the laundry to a cupboard off a living area or circulation space to improve the connection to outdoors or allowaccess to future additions.
Further thermal performance considerations
New additions to your home require detailed thermal performance design to make sure they integrate with the renovation improvements to existing sections.
Consider engaging a building sustainability assessor to model the whole home if this has not already been done during the concept design stage. Most states now require that minimum sustainability benchmarks be met as a condition of approval for substantial additions. While a NatHERS rating may not be required, it provides valuable input to your design development process.
Building sustainability assessment software
Often a single room or window can result in unwanted summer heat gain or winter heat loss. Building sustainability assessment software can model various window sizes, orientations and glazing types to help you see which combinations add thermal comfort most cost-effectively.
Windows and glazing
- Fine-tune the size and orientationof your windows. Minimise the size of east- and west-facing windows and maximise the north-facing windows that receive the most sun. Where solar access is unavailable, use only moderate amounts of glazing, consider low mass construction and maximise insulation levels (see ‘Design for climate’, ‘Orientation’ and ‘Glazing’).
- Specify appropriate glass typefor climate and each orientation. Orientation-specific glass types are often used to overcome adverse orientations or to capture views. Check that climate-appropriate Solar Heat Gain Coefficients (SHGC) and U-values are specified (see ‘Glazing’).
Finalising your design and work with your builder
For more details on the specific guidance below on finalising design documentation, tendering for a builder and the renovation construction process, see ‘The design process’ and ‘The construction process’.
Design detailing and documentation
Complete your design before beginning this stage. Design changes made during this stage may add to design costs.
Start by revisiting the environmental goals specified at the concept stage to ensure that they are carried through to the detailed plans and specifications. These will be submitted to Council, tendered by builders, and annexed to your building contract.
Choosing a builder
Before choosing your builder, see the detailed information in ‘The construction process’.
Building a new home and renovating one have much in common, but your renovation and addition builder needs a set of specialised skills which vary depending on the stage you’re at.
In many households, there’s a would-be builder or renovator. But beware – rewarding as DIY may be in terms of creative expression or skill building, inexperience often leads to unforeseen social, environmental and financial costs.
Popularised by home renovation TV programs, renovations are often made to look easier than they are, and lifecycle outcomes from amateur renovations can be poor. Critical medium- and long-term details, such as thermal performance or water and energy efficiency are commonly overlooked to achieve a quick turnover, which may cause the problems to be passed on to the next owner.