Tree Houses & Play Houses

A tree house or play house is an accessory structure that is permitted on a single-family property.  Tree houses and play houses must meet the following zoning requirements.  Please contact the Community Development Department at (847) 853-7550 or at comdev@wilmette.com to discuss the specific zoning regulations that apply to your property.

Building Permit Required

To ensure that a play house (accessory structure with ground supports) is meeting the zoning and building requirements, a building permit is required when:

  • the structure has supports to the ground or
  • is to be supplied with electricity and/or water

A tree house (accessory structure supported solely and entirely by a tree or trees) does not require a building permit unless it is to be supplied with electricity and/or water, but is required to meet the zoning requirements described below.  To help ensure that your proposed tree house meets zoning requirements, contact the Community Development Department at (847) 853-7550 or atcomdev@wilmette.com.  If possible, please have your plat of survey available.

Zoning Requirements

Defined: The Zoning Ordinance does not specifically define a tree house or a play house.  Such structures are regulated under the provisions of accessory structures.  The Zoning Ordinance has been interpreted such that a tree house is considered an accessory structure that is supported solely and entirely by a tree or trees.  If the structure is supported by a tree or trees but also has any support directly to the ground, it is considered a play house.

Setback requirements: Setback requirements vary by the size and shape of the lot, the zoning district, and whether it is a corner lot, interior lot, or double frontage lot.  Tree houses and play houses are not permitted in the required front yard, side yard adjoining a street, or minimum side yard.  Tree houses are allowed in a required rear yard.  Please contact the Community Development at (847) 853-7550 or at comdev@wilmette.com for help determining what the required setbacks are for your property.  If possible, please have your plat of survey available.

Maximum height: Tree houses and play houses, as accessory structures, are permitted up to 15.0′ in height from adjacent grade to the highest point of the roof.

Impervious surface coverage requirements: Play houses (accessory structures with ground supports) must meet the impervious surface coverage requirements, which are based on their location on a lot.

Total lot coverage and floor area: Play houses (accessory structures with ground supports) may be counted as square footage for lot coverage and floor area.  The maximum permitted lot coverage and floor area vary by lot size.

Separation from house: Play houses (accessory structures with ground supports) are to be a minimum of 10.0′ from the nearest wall of the house.

Separation between accessory structures: A minimum of four (4) feet separation is required between roofed accessory structures as measured from the walls of each structure.

Maximum number of accessory structures: Lots less than 15,000 square feet in area are permitted two (2) detached accessory structures; lots 15,000 square feet or greater in area are permitted three (3) detached accessory structures.  The following structures are counted as accessory structures for the purpose of this requirement: detached garages, gazebos, coach homes, beach houses/cabanas, boat houses, sheds, swimming pool equipment sheds, detached pergolas, and similar structures.

Maximum size of roofed accessory structure: Play houses, as a roofed accessory structure, may not exceed 200 square feet in area.