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Affordable architectural advice and design for
homebuyershomeownersproperty professionals

Technical and planning advice to explore the full potential of your property, on time and within your budget.

Get in touch

Advice for



  • Assistance and explanation of the professional jargon in the survey:
    Homebuyers Report (Level 2) or Building Survey (Level 3).
  • Explaining the survey findings and answering buyer’s questions, discussing the action plan for the buyer.
  • Advice on cost estimate and time scale of remedial works.
  • Arranging documents and cost estimates for selling price reduction (reduced offer based on the survey findings).
  • Advice on cracks, subsidence, hidden issues.
  • Cost plan for remedial works or full refurbishment.
  • Advice on the house potential: possible extensions and conversions, specific planning and building regulations, conservation area limitations.
  • Finding traders and obtaining quotations, describing works that should be quoted for, comparing traders quotes, summarising remedial works.

Advice for



  • Obtaining planning permission for larger extension.
  • Obtaining retrospective planning permission.
  • Advice and planning permissions within conservation areas.
  • Building regulations advice, smart ideas on how to comply with the requirements.
  • Designing loft extension, side return extension, garage conversions.
  • Designing garden studios: home office, music studio, home gym.
  • Lighting layouts and electrical plans.
  • Efficient kitchen design, 2D and 3D drawings.
  • Modern bathroom designs, 2D and 3D drawings.
  • Ideas for maximising storage space.
  • Elegant interior design and lighting ideas.
  • Cost plan.

Advice for



Advice on maximising rented space including permitted development applications and planning permissions:

  • Flat conversion (dividing house into flats or self contained studios).
  • House in multiple occupation (HMO).
  • Extensions.
  • Large room conversions.
  • Kitchen and bathroom space saving ideas.
  • Garage conversions.
  • Change of use.

Advice on commercial to residential conversions:

  • Feasibility studies.
  • Prior approval application.
  • Initial cost appraisal.
  • Documentation for permitted development and lawful development certificate.
  • Description of works and construction programme.
  • Finding traders and obtaining quotations.

Architectural presentations, professional presentations for clients and investors:

  • Assistance for Deal Packaging.
  • Portfolio presentations including photos and floor plans.
  • Graphical representation of data and deals.
  • Tradespeople quotations and programme.
  • Work presentations including before and after photos.
  • Architectural drawings, 2D and 3D, image editing, visualisations.
  • Printable and online presentations.

About me

Katja Leszczynska

Dipl. – Ing. Arch (ARB), MSc LL

I am a qualified Architect and Lighting Designer with a focus on smart home integration.

I have a passion for helping people to achieve their vision. I work with a wide range of clients from homebuyers to homeowners and property professionals, to help and maximise their property’s full potential.

After graduating in Architecture from the HafenCity University in Hamburg, I worked in Germany and Spain with architectural and lighting design practices, delivering residential and commercial projects across Europe.

In 2008, I settled in London and since then I have worked on a wide range of projects including major student residential schemes, as well as commercial, hospitality and a variety of residential projects. My area of expertise ranges from feasibility studies and planning to execution and construction supervision.

After buying and fully refurbishing my first property in 2014, I have focused on residential conversions. I have extensive knowledge about local building fabric, building types and I always look for opportunities to expand and add value to the properties.

Key skills

  • Clearly communicating design ideas.
  • Efficiently managing project deliverables.
  • Extensive understanding of the architecture and planning process.
  • Comprehensive knowledge in the latest technologies and building regulation requirements.
  • Languages: Polish, English, German and Spanish.


  • Bartlett School of Architecture, UCL, London.
    Master’s degree in The Built Environment Light and Lighting,
    MSc LL, 2010
  • HafenCity University Hamburg, Germany, Faculty of Architecture,
    Dipl.-Ing. Arch, 2006

“Katja was great in providing level-headed, thoughtful help to us at a time when issues found in the Structural Survey were very scary. She just put things in perspective, in a very human, non-jargon way and explained that almost everything can be talked about and negotiated.”

Shi-Ning, Haringey

“Totally love Katja’s style and attention to detail. Having seen many of her previous projects, I would definitely recommend her services.”

Andreea, Enfield

“Katja was fantastic in creating several design options for a new built family home and art studio. She quickly understood our family requirements and was patiently explaining to us various design scenarios and implications of any changes. The whole design process was very smooth and time efficient. We are very grateful Katja was introduced to us by our friend and we would highly recommend her services.”

Krzysztof, Hounslow

“Katja did an amazing job for me when I was applying for planning permission. She did the planning application drawing within the short time frame and to the highest professional standards. I would use her services again and highly recommend Katja.”

Cam, Haringey