What are the 3 main site costs I need to consider when building a prefab home?

3 main costs involved in building a prefab home

Building a prefab home is a big decision, and the site costs involved are sometimes some of the more significant costs involved in developing a new manufactured home.

The trick here is that most modular or prefab builders will give you pricing for a home EXCLUDING the site costs. Also, we think that is somewhat misleading as the price of the house could quickly end up being $20,000 to $100,000 or more depending on your land.

So, read on to find out the top 3 main site costs you need to consider before buying a prefab home!

Site Cost #1 – Electricity

 site cost 1 onsite power connections to modular homes

The first thing you need to consider is the cost of getting power connected to your new modular home. Depending on your site this can vary immensely; however, we’ve found that you can generally break this into three main categories.

In-town power

in town power connections and solar power

If your site is in an urban area, you can usually connect power to your new manufactured home quite inexpensively. If your home will be within 20m of the pole and there is a clear space the cost of joining your electricity could be quite inexpensive. Moreover, this can also be swung across overhead to a riser bracket or a property pole.

Acreage Power

underground power onsite for the relocatable homes another site cost

If your home is a little further away from the power pole, then the cost does increase. Usually, on acreage block, the power will be swung across to a property pole on your site then run underground a longer distance to your home and sheds.

Off-Grid Power

Solar power options for prefab homes

If you have to run your power a longer distance (200m+) we’d recommend that you consider an off-grid solar power system. While this is the most expensive option, you do get the benefit of not having to pay a power bill ever again!

A well-designed solar power system will also provide more than enough power to run your home and will have backup batteries and generators for those cloudy days!

Site Cost #2 – Plumbing & Drainage

Plumbing & Drainage costs for modular homes - site costs

The next major onsite cost you need to consider is your plumbing and drainage. Moreover, this will include your sewerage work, septic tanks, water tanks and pumps. So, we can break this into two categories urban sites with town services and acreages with out town services.

Town Sewer & Water

in-town sewerage and power for modular homes

So, for sites with town sewerage and water, the cost for your onsite plumbing will be minimal. We find that the only additional items required may be a water tank and pump depending on your local councils’ requirements.

Onsite Sewerage Treatment Plants or Septics

how a treatment plant works in manufactured homes

Most acreage site will require some form of on-site sewerage treatment. The main system options available to our clients are the “old style” Septic Tanks or an Aerated Wastewater Treatment System (AWTS). Most councils, plumbing designers and plumbers recommend an AWTS system nowadays although in some rare cases a septic tank may be prescribed.

Water Tanks

poly water tanks for modular homes in qld and northern new south wales

The additional site cost you will need to consider for acreage sites is the need for water tanks. We recommend you consider attaching at least two 22,500L poly water tanks with a pressure pump to your home and shed if you do not have town water! The last thing you want is to be trucking in water in a dry spell!

Site Cost #3 – Sheds

colorbond sheds on acerages with westbuilt homes

Lastly, consider your requirements for sheds and carports. Depending on your needs, we recommend a minimum 6m x 6m shed for acreage sites. On in-town blocks, you may want to consider building a garage into the main home – speak to Westbuilt consultant about your options in this regard!

Another option is to put a carport on the side of your home. Westbuilt can facilitate this to integrate it with your new home or organise a standalone shed

Honourable Mention – Council requirement site costs

council requirements for modular buildings can cause additional cost

The last site cost we’d recommend you think about is what council requirements affect your site. Importantly, things like landslip, bushfire, flood, environmental overlays may affect your site and could increase your cost substantially! Check out an article about finding the perfect home site!


completed prefab home with colorbond shed, poly water tanks and septic system

So, as you can see, there is quite a bit to consider when thinking about the additional costs involved in a building your perfect home!

We get it; it’s not easy to build a new home. There is so much to think about and consider. And, this is why we offer a couple of packages to our clients to help them get certainty and de-mystify the whole building process:

The Turnkey Package

modular home with library, solar power, solar hot water, carport and verandahs

This package is for the client who doesn’t want to have a hassle. The team will investigate your site requirements, speak with local plumbers and electricians, plumbing designs and provide you with a total price on connecting power and water to your home. So, ask your design consultant today about more information on this.

Site Analysis Package

site analysis package by westbuilt to help find out site costs

The site analysis package is for those clients in the earlier stages of choosing to build a home. Also, by choosing this package our clients will receive a detailed report on the potential council or transport issues presented by your site.  We will also look at what the potential costs are and also find the ideal building location for your home on your site. Ask your design consultant today about more information on this.

Building Design Package

custom modular home design services by westbuilt

If you’re struggling to design the perfect home for yourself, we recommend you get in contact with our building design team. Find out more here!


If you have your own vision for your house, we are happy to work with you to design the perfect layout that is tailored just for you.


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