How to Add an Extension on to Manufactured Homes

One can add a porch, garage, extended living space or separate guest home onto their manufactured home. The important factor is that all additions must be built as a separate entity. This means their structural support (and utilities if possible) are completely independent from the main home and can stand on its own. This is to prevent the risk of damage by adding more than the manufactured home was designed to physically handle.

Image from Mobile home additions guide: ideas, cost, pictures, floor plans | Homes Direct (

Settling into your manufactured home, you may realize you want to expand the space a bit, add an enclosed carport or enjoy mornings out on your porch.

These can add great value to your home life and selling price later on! However, there are a few building and safety factors to consider.

Safety & Structural Considerations

HUD codes for building manufactured homes state that all additions whether a car garage, porch or awning must be connected to the home in a way that they are able to carry their own weight and not rely on the home for structural support. This means they’ll have their own foundation system as stand alone structures. This is because your manufactured home was not designed to carry more than its weight, let alone a whole new structure. This can create great damage to your home as time passes. (1)

A few other things you’ll need to check are whether your addition needs to be weather proofed like a deck or patio and check whether you’ll need to alter or add on to your electrical and/or HVAC systems. Consult a professional contractor for these, to ensure your systems are equipped to meet the added demand. (1)

On the plus side,…

There are no HUD standards to follow with regards to home additions!

Once manufactured homes leave the factory with that HUD approval for construction, they no longer have any control over your home. (2)

Be mindful that your home was carefully crafted according to your local building regulations, soil type and wind zone even. Your new structure may need all these considerations as well to stand just as resilient.

The safest way is to always check with your local building codes on the requirements you need for your gazebo, carport or porch. These might need some permits or inspections so it’s always a good idea to check before getting into it!

Here are a few rules to keep in mind and close to heart!

  • Have A Minimum of 2 Exits: Manufactured homes must always have at least two exits. Often, home additions would attach to the back door, covering up that last exit, which is a big no no in safety egress for emergencies.
  • Free-Standing Structure: The home addition must be able to withstand its own weight, roof and wind load and transmit that load onto its own foundation, and not the main home.

The structure should have a minimum of 4 footers: 1 per corner to safely transmit the load down. The depth of  your foundation is determined by the frost line or soil load bearing capacity (how much weight your land can take).

Find more details in the HUD Guide on Manufactured Home Foundations. (3)

  • Independent Electrical Wiring & HVAC Systems: Tapping into the main unit’s electrical panel for your new spaces will not only be a safety hazard but also violate HUD standards and local building codes. The same goes for your HVAC. Consult a professional for the extra ductwork and vents to make them work and not interfere with the main home.
  • Ventilated Skirting: Your new addition may block off some ventilation points for your skirting. This can lead to mold problems and excess water that can damage the home. Remember your skirting protects the home’s underbelly wherein the structural and utility lines all run to keep the home functioning.
  • Changes that Void Warranty: Be mindful that many changes unauthorized by your home center can automatically waive you of your warranty. This also benefits you to approach your dealer for any additions so that you may still stay within the lines of your warranty or changes they approve and render safe.
  • Mindful of the Connection & Opening: Be mindful of the opening you create to connect to your added section. A bigger opening means you’re cutting away at more structural elements! So it’s best to limit that to a doorway if possible, to avoid adding in support beams, columns, etc.
  • Seal it Up Well: After making that connection and building incredibly close (but not directly attached), seal up the old and new sections with some weatherstripping, flashing, caulking — anything to prevent moisture and air leaking!

Image from Ultimate Guide to Mobile Home Additions – Mobile Home Living

The image above shows an addition you should not do as it adds all its weight onto the existing unit.

Compare that to the images below, wherein the added structure is completely independent from the main unit.  (3)

Images from 

“To put it simply, you aren’t attaching the addition to the home at all, you are building extremely close to the home and then sealing the crack between the home and addition to prevent air and moisture leaks” (2)

Why Expand and Add?

As the family grows maybe you’d like to add another bedroom, bigger living room or have a nice outdoor porch to enjoy. This is a great solution if you need more space, but don’t necessarily want to upgrade from a single to double wide, which would cost much less.

Some people also find themselves settling in their location longer than they anticipated. Initially getting their manufactured house as a temporary home, but having grown attached to the community and neighborhood, decided to just add onto the house to make it their permanent abode. (4)

How to Do it?

First figure out what additions you’d like. Will you make good use of this space? Can an existing space not fulfill this activity?

Next look for home centers that can build out your modular rooms to attach. Perhaps where you bought your manufactured home can recommend some people! Have them help you find a good contractor to work with. (4)

Make sure to take photos of your existing home and communicate those spaces on your wishlist.

The easiest way to go about it is searching through the floor plans your home center already has to offer. They might not have exactly what you’re looking for, but finding one closest to what you want and tweaking it from there will save a lot of time and money in the long run.

An additional 900 square feet can approximately be done in two to three months, after obtaining all the necessary paperwork and permits. Remember these add ons and hanging roofs still need to be state and code compliant! (4)

These must all be free-standing with only the flashing connected to the main home. The anchoring connections, materials and designs will also be for approval. All installations will be done by a licensed installer, contractor or engineer.

Home Addition Ideas

To be sure these additions are worth your time and money, here are some great, functional upgrades that can boost the aesthetic, comfort and overall value of your home. (5)

1.   Upgrade the Skirting and Siding

Not only do these add to your curb appeal, giving a site built home, it also improves the heating and cooling of your home, lowering those energy costs! Weatherproof, insulated skirting will always be a top priority as this protects your home’s underbelly from critters coming in, freezing pipes and moisture accumulation.

2.   Extra Insulation

Newer homes don’t need to concern themselves with these as the HUD Code enforces strict insulation requirements. However several older mobile home models suffer from a lack of insulation, leading to skyrocketing energy bills and an uncomfortable temperature indoors.

Adding some insulation to your walls, underbelly and roof will increase your indoor comfort, reduce the energy bills and up the resale value. Also check for any cracks and gaps. Sealing these will drive up its efficiency.

3.   Energy Efficient Upgrades

Replacing your appliances to energy star rated or inverters are a great start at regulating indoor temperatures and keeping energy bills down. The next step would be upgrading your doors and windows to those that reduce air drafts, let in less heat, which will dramatically save you money on heating and cooling costs.

4.   An Extra Room

This entails a lot of money and could add onto your running costs. Take a look at our piece on hybrid spaces. An additional room would be of great value if it serves as your home office, gym and occasional guest room for when that relative comes over to visit!

It can be scaling up and doubling up your space, but perhaps it doesn’t need to be a whole new room and it can just be adding a nice long porch to enjoy the outdoors.

Image from Pinterest

Other Things to Watch Out For

As previously mentioned, opting to add onto your home may waive all your warranties. Another danger as far as manufactured and mobile homes are concerned, it’s never a guarantee that your resale value will increase with all your upgrades. So be sure that these improvements directly benefit you and are not solely for the future turnover.

This can change if you’ve opted to convert your home from personal property to real estate. As home loans and financing are always more tricky for manufactured homes. (5)

It also pays to research if your insurance and taxes will change with these additions you make. Especially if you’re converting it into real estate property, your real property tax will increase.

Can you still move around your home with all those additions?

You CAN move these additions with you if they were properly built. If not, more often these are left behind on site (so that’s another investment cost to bear in mind).

If you’re also abiding by building code and health regulations, one can live in their home as the renovations are being done. Anyway, it’s supposed to be a separate entity on its own! (5)

Ultimate Guide to Mobile Home Additions – Mobile Home Living Shows great content on the joinery details and connection of sealing and roofing your addition.

Best of luck and enjoy your home!

Image from Building a Two-Story Addition onto a Manufactured Home (


  1. C, M. (2021, February 26). Should you add on to your manufactured home yourself? Adding on to Your Manufactured Home l Clayton Studio. Retrieved June 2022, from
  2. O’Dell, C. (2019, February 14). Mobile home additions and hud- what are the rules? Mobile Home Friend. Retrieved June 2022, from
  3. Crystal. (2022, February 21). Ultimate Guide to Mobile Home Additions. Mobile Home Living. Retrieved June 2022, from
  4. Homes Direct. (2022, February 10). Mobile Home Additions Guide. Homes Direct. Retrieved June 2022, from
  5. Trembath, N. (2020, May 22). Upgrades that can increase the value of your manufactured home. Triad Financial Services. Retrieved June 2022, from