adding a two story addition to a ranch house

Foundation Requirements for Adding a Second Story

foundation requirements for adding a second story
foundation requirements for adding a second story

Over time, probably years after erecting their buildings, homeowners may begin considering adding a second story.

This consideration may arise from the need to create more accommodation in an area with limited land space, the need to create more rooms in their houses without having to spend money in laying a new foundation, or the need to make their property taller and have it designed to their taste.

Most times when buildings are inherited or the ownership is transferred to a new owner with a larger family, the new owner may need to add a second story to the building, especially when it’s a high-income earner.

They may need to include some special-purpose rooms such as the gym room, library, game room, and so on. Some may carry out the procedure just to increase the value of their property.


The Major Types of Foundations

There are two major types of foundations; houses are usually built using either shallow or deep foundations. It's important you know the one your house is built on.


  • Shallow Foundation

They are about 1.5 meters deep into the soil and are relatively cheap to lay. The load they carry is not transferred into the deep part of the ground, unlike the deep foundation. Examples are the raft foundation, trench foundation, and strip foundation.


  • Deep Foundation

This type of foundation is made to reach deep into the soil where the inner layer of the soil is far better than the top layer. It is mostly used for high rising buildings and buildings intended to bear a lot of weight.

Areas that have unsuitable soil use this type of foundation. Examples are the drilled shafts and pile foundations. This is a better option for story buildings.


Adding a Story

how to build a second floor on an existing house


The practice of adding a story on an existing building isn't new and has been thriving mainly in cities that have small landmass but overwhelming populations. It can be a safe procedure if carried out properly under the supervision of a structural engineer. However, a thorough and practical knowledge of the requirements is needed.

A valid concern in the heart of homeowners who wish to carry out this construction on their buildings is if the foundation of their buildings will be able to support an additional story. It's normal to get skeptical about the foundation of an old building bearing the weight of a story.

This article will give you a comprehensive list of requirements for your foundation to bear another story. Before then, listed below are the importance of having a strong foundation for your building.


Importance of a Strong Foundation

It Provides Stability

The foundation of a building can be likened to a rock on which a house is built. It's made to be solid in such a way that even if the building were to be a high rising one, it won't sink into the soil. It receives weight from the building and distributes it into the soil.


It Holds the Structure Upright

The foundation of a building is the reason a building remains upright, even after decades. This is why it requires lots of resources to lay. With a good foundation, the fear of an eventual collapse is eliminated.


A Defense against Natural Disasters

Natural disasters are unavoidable and are what we experience from time to time. The foundation of a building keeps it standing when it's being flooded with water, when there's an earthquake close by, or when the wind is too strong and threatens to pull off the building. The strong concrete slab is also designed to resist heavy shock.


It Keeps Moisture Away

It's normal for water to gather at the base of your building after rainfall. And for buildings whose walls are fully or partially made from wood, a solid concrete foundation keeps water away. However, a sturdy foundation should be built alongside proper drainage that will channel out excess water.


Foundation Requirements for Adding a Second Story

With the knowledge of the importance of a solid foundation, you will be able to appreciate more the requirements prescribed for adding a second story to your building. They’re listed below.


second story additions

Get an Approval from Relevant Government Authorities

Getting approval from the town planning agency in your town is the first and probably the most important requirement before you begin. Not all town planning agencies usually approve of adding a second story on an already existing building.

Some agencies may insist on verifying the solidness of your foundation before approval. The agencies concerned may also demand periodic supervision of the project to ensure that the building meets the government's prescribed standard.

Some homeowners who chose to bypass the government's approval have had the government demolish their properties. Aside from the possibility of the building being substandard, your story building plan may not be in resonance with the government's plan for your town or region.

An approval from the government will save you from unnecessary stress and interruptions, and it will set you on track as far as your project is concerned.


Get a Compatible Design

After getting your permit to build, contact a structural engineer to give you a suitable design that will fit your already existing structure. The design should take into consideration pillars and staircases to be erected. It will inform the kind of modifications that will be done on the foundation.

The design should also consider the extra load the additional story will come with. The type of roofing and intended use of the rooms upstairs will determine the kind of solidification that will be done to the foundation so that it will be able to bear the new weight conveniently.

The structural engineer in the course of designing the new story may also advise you if you should go on with the idea of the project, if the cost of carrying out the project outweighs the usefulness of the additional story, or if it will be better to rebuild your building anew.

It is worthy to note that projects of this nature are financially tasking and may gulp more money than presumed.


Carry out a Soil Test

It may have been decades since you last carried out a soil test for the soil around your home, probably the time you were erecting your house. As of that time, the soil nature may have been fit for the house it currently carries.

Now that you’re about to add another story, you must call an expert to determine if the present soil condition can contain the weight of your intended building.


Determine the State of the Foundation

You must check for cracks, rusting irons, and molds in your foundation. Irregularities such as this may indicate a weak foundation. If weak, the foundation needs to be repaired before an additional story can be added. In a severe case, the idea of strengthening the foundation has to be discarded and a new building erected.


Grout the Soil

To further strengthen the foundation, the soil around the foundation can be grouted by injecting concrete into the ground. This will help solidify the soil around it.


Repair the Foundation of Your Building

As awkward as it may sound, you must carry out repairs on your building's foundation. Check the footings and increase their width and thickness to standard. If the foundation has been flooded with water, it should be drained, as water may cause the irons to rust faster. Additional piers, footings, and beams should be added where required.


Factors to Consider Before Carrying Out this Project

foundation requirements for adding a second story


This kind of project requires a lot of expertise. Its financial implication may be overwhelming and may not be a match for the result. House owners willing to undertake this conversion on their building must be ready to bear unforeseen expenses. The cost of erecting a new house may also be compared to the intended expenses of re-strengthening an already existing foundation.


Temporal Residence

During this procedure, the occupants of the house will be required to relocate temporarily to a new house. Issues about the foundations of a building are not done in a hurry. It may take time to get it ready.


Availability of Experts

This procedure must be carried out only by qualified personnel. The availability of such personnel may be scarce or not within reach at the desired moment. It's best to put the project on hold till you can get an expert.



Adding a second story to your building isn't an unusual decision and is in no way going to affect the standard of your building. Projects of this nature only require you to follow already established procedures. Such a decision should be taken after a personal study and conviction.

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