With over 60 years of combined experience, SLH High Voltage and Civil is the leader in the high voltage space. Whether overhead or underground, our expertise in pole line and substation design and construction – as well as all things low, medium, or high voltage, makes SLH the number 1 choice.


We proudly serve following regions in Ontario:
- Belleville
- Brockville
- Cobourg
- Durham Region
- Guelph
- Haliburton
- Hamilton
- Kawartha Lakes
- Kingston
- London
- Napanee
- North Bay
- Ottawa
- Oxford County
- Peel Region
- Perth
- Prince Edward County
- Sault Ste. Marie
- St. Thomas
- Sudbury
- Timmins
- Walkerton
- Brant County
- Chatham-Kent
- Cornwall
- Essex
- Haldimand-Norfolk
- Halton Region
- Huron County
- Kenora
- Kitchener-Waterloo
- Muskoka
- Niagara
- Orangeville
- Owen Sound
- Parry Sound
- Pembroke
- Peterborough
- Sarnia
- Simcoe County
- Stratford
- Thunder Bay
- Toronto
- York Region