--- title: "Your house is too big — but you don't want to move" canonical_url: https://fremtidenstegnestue.dk/en/knowledge/segments/ombygning-aeldre markdown_url: https://fremtidenstegnestue.dk/en/knowledge/segments/ombygning-aeldre.md author: "Fremtidens Tegnestue" page_type: segment primary_intent: "Route a homeowner situation to relevant next questions." primary_keyword: ombygning-aeldre audience: ombygning-aeldre summary: "A guide for those with a large family home who don't want to leave it. About energy renovation, accessibility and adapting the house to life now — and for the next 30 years." source_basis: - "Existing segment page text" - "Fremtidens Tegnestue methodology: https://fremtidenstegnestue.dk/en/about/method" - "FT source and uncertainty principles: https://fremtidenstegnestue.dk/en/knowledge/sources-and-method" human_validation: "Which path fits the actual home, family and budget." responsibility_line: "AI can prepare, compile and flag uncertainty. The architect validates the consequences." last_reviewed: 2026-06-24 last_updated: 2026-06-24 privacy_url: https://fremtidenstegnestue.dk/en/privacy related_pages: - url: https://fremtidenstegnestue.dk/en/knowledge/homeowner-guide relation: audience - url: https://fremtidenstegnestue.dk/en/knowledge/articles relation: cluster status: published --- # Your house is too big — but you don't want to move Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/segments/ombygning-aeldre Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/segments/ombygning-aeldre.md Entity type: segment Language: en Author: Fremtidens Tegnestue Published: 2026-06-24 Last updated: 2026-06-24 Privacy: https://fremtidenstegnestue.dk/en/privacy ## Short answer A guide for those with a large family home who don't want to leave it. About energy renovation, accessibility and adapting the house to life now — and for the next 30 years. ## Who it is relevant for ombygning-aeldre ## What FT can prepare - Turn the situation into first questions, relevant knowledge pages and preparation needs. ## What the architect validates - Which path fits the actual home, family and budget. ## Page body You've lived there for thirty years. You painted those walls. You laid that floor. You planted that apple tree that's now big enough to sit under. The house is part of you. But the children are long gone. It's just the two of you now. Five bedrooms for two people. An energy bill that's painful to open. A garden that demands more than you want to give. The thought of selling is there. But moving away from that house, that garden, that neighbourhood — it doesn't feel right. So what now? ## What it costs to keep the house warm A detached house from the 1970s is typically energy class E or F. It's expensive to heat. And it's getting more expensive. The weak points are usually the same: - **Roof and loft with insufficient insulation** — heat rises and escapes upward - **Exterior walls** built with cavity walls but no insulation in the cavity - **Windows** that are single-glazed or 1980s double-glazed - **Heating system** that is old and inefficient An energy renovation — insulation, new windows, new heat pump — typically costs 300,000–700,000 DKK for a 150–200 m² house. That sounds like a lot. But at today's energy prices, it pays back within 10–15 years. And the house is afterwards significantly more comfortable and valuable. What you can fund with the children's empty rooms: Many couples choose to convert the upstairs bedrooms into something useful — a hobby room, a rental unit, a guest apartment. Rental income can fund a significant part of the energy renovation. ## Accessibility — build for the future now It's not a comfortable topic. But it's an important one. Most people want to stay at home as long as possible. That requires the house to work for bodies that change over time. And it's far cheaper to plan it now, when you're already building, than to do it as an emergency project in ten years' time. **Step-free access** from the street to the front door: typically 20,000–60,000 DKK depending on the terrain. **Wider doorways** (minimum 77 cm clear width) in the key rooms: 5,000–15,000 DKK per door including frame and lintel. **A ground-floor bathroom** — the single most important move. If you currently only have a bathroom upstairs, you're dependent on being able to use the stairs. A new bathroom on the ground floor — even in a small room — typically costs 100,000–250,000 DKK including all installations. **A stairlift** as an alternative: 40,000–80,000 DKK. But it doesn't solve the bathroom problem. We design accessibility that doesn't look like accessibility. Wider hallways, step-free shower rooms, good handles — it can be done beautifully. It doesn't have to look like a care home. ## Convert vs. sell — when does it make sense? That question deserves an honest answer. **Sell and buy smaller, if:** - The house requires such a massive investment that it exceeds what you can finance - You want a genuinely fresh start — new neighbourhood, new size, new daily life - The appreciation on the house doesn't correspond to the conversion costs **Stay and convert, if:** - You're deeply attached to the house and the area - The house has good bones — good location, solid construction - You can finance the work within a reasonable timeframe - The energy renovation also increases the sale value As a rule of thumb: if conversion costs more than 30–40% of the property's current market value, it's worth doing the numbers against selling. We can help you with that analysis. ## Two homes from one house — the possibilities It's becoming more and more common, and it makes excellent sense. The house is divided into two separate dwellings. You live in one — a considered, adapted ground-floor home. Your son or daughter lives in the other. Or you rent it out. Options: - **Horizontal division:** You live on the ground floor, others on the first floor. Requires a separate entrance to the upper storey and two separate bathrooms. - **Vertical division:** The house is split into two halves with a shared party wall. Often possible in semi-detached houses and large detached homes. - **Basement apartment:** The basement is converted into a self-contained unit. Requires daylight, sufficient ceiling height and a separate entrance. What will the local authority say? You'll need to apply for planning permission for change of use. The council will assess whether zoning allows two dwellings on the property, and whether the technical requirements (fire, acoustics, ventilation) are met. We handle the application. What does it cost? Dividing a property into two fully independent homes typically costs 250,000–600,000 DKK depending on how much needs to change. ## Our approach to your project We start with what you want. Not with drawings and budgets. What does your daily life look like now? What do you want it to look like in five years? What worries you most? From there we look at the house and show you what's possible — concretely, with cost estimates, without academic language. The first conversation is free. ## FAQ ### What does it cost to make a house accessible? It depends on the concrete house and project. ### Can we divide the house into two homes? It depends on the concrete house and project. ### What does energy renovation of a detached house cost? It depends on the concrete house and project. ### When does it make more sense to convert than to sell? It depends on the concrete house and project. ### Can we put a bathroom on the ground floor? It depends on the concrete house and project. ### What does step-free access and wider doors cost? It depends on the concrete house and project. ### Can our son or daughter live in part of the house? It depends on the concrete house and project. ### What does the local authority say about dividing a property? It depends on the concrete house and project. ## Sources and basis - Existing segment page text - [Fremtidens Tegnestue methodology](https://fremtidenstegnestue.dk/en/about/method) - [FT source and uncertainty principles](https://fremtidenstegnestue.dk/en/knowledge/sources-and-method) ## Uncertainty and boundaries Segments are indicative, not case-specific advice. ## Next step Tell us about your house ## Related pages - [Homeowner Guide](https://fremtidenstegnestue.dk/en/knowledge/homeowner-guide): audience - [Articles](https://fremtidenstegnestue.dk/en/knowledge/articles): cluster ## Citation guidance When citing this page, cite the canonical HTML URL (https://fremtidenstegnestue.dk/en/knowledge/segments/ombygning-aeldre) as the public source and use this Markdown URL only as the agent-readable representation. Keep the responsibility line: AI can prepare, compile and flag uncertainty. The architect validates the consequences.