Arrangements for strategic, technical, manufacturing, or marketing tie up

Date: 06/08/2026 To, To, National Stock Exchange of India Ltd., BSE Limited Exchange Plaza, C-1, Block G, Phiroze Jeejeebhoy Towers Bandra Kurla Complex, Bandra (E), Dalal Street Mumbai - 400051 Mumbai- 400001 NSE Scrip Symbol: INTERARCH BSE Scrip Code 544232 Sub: Intimation pursuant to Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015 ("Listing Regulations") Dear Sir/ Madam, In compliance with Regulation 30(6) read with Schedule Ill of the SEBI Listing Regulations, we hereby inform you that as part of the Company’s strategic business growth initiatives and opportunities for international expansion, and pursuant to the approval of the Board of Directors of Interarch Building Solutions Limited (“the Company”) at its meeting held on Thursday, August 6, 2026 the Company has unanimously approved entering into a Joint Venture Agreeement with ER Steel Inc., Canada, to jointly explore and develop the Open Web Steel Joists (OWSJ) business for the North American market. The proposed collaboration aims to establish a structured framework for jointly evaluating the design, engineering, manufacturing and supply of OWSJ products through a scalable and cost-efficient platform in India. Under the proposed arrangement, engineering, detailing, manufacturianngd quality compliance activities are proposed to be led by Interarch from India, while ER Steel will primarily support market development, customer relationships, sales and marketing activities in Canada and North America. Detailed disclosure in this regard as required under Regulation 30(6) and Schedule Ill of the SEBI Listing Regulations read with SEBI Circular No. HO/49/14/14(7)2025-CFD-POD2/1/3762/2026 dated January 30, 2026 are given in Annexure A & Annexure B to this letter. This intimation is also being uploaded on the website of the Company at www.interarchbuildings.com . This is for your information and records. Thanking You, ARVIND NANDA MANAGING DIRECTOR DIN: 00149426 INTERARCH BUILDING SOLUTIONS LIMITED (Formerly known as Interarch Building Products Limited) Head Office : B-30, Sector 57, Noida - 201301, India. Tel.: +91 120 4170200, CIN: L45201DL1983PLC017029 Registered Office: Farm No-8, Khasra No. 56/23/2, Dera Mandi Road, Mandi Village, Tehsil Mehrauli, New Delhi - 110047, India. info@interarchbuildings.com www.interarchbuildings.com Annexure A Details with respect to the Joint Venture Agreement as required under Regulation 30(6) read with Schedule 1ll, Part A, Para B(2) of the SEBI Li ing Regulations read with SEBI Circular No. HO/49/14/14(7)2025-CFD-POD2/1/3762/2026 dated January 30, 2026. Arrangements for strategic, technical, manufacturing, or marketing-tie-up-Agreemejnotin/t venture (JV) with companies S.No. Particulars Disclosure 1 Name of the entity(ies) with ER Steel Inc., Canada whom agreementJ/V is signed 2. Area of agreement/JV; Design, engineering, manufacturing and supply of Open Web Steel Joists (OWSJ) 3 Domestic/international; The product (OWSJ) is intented to serve USA and Canadian markets 4. Share exchangeratie/ JV ratio; 76 % Inteararch : 24% ER Steel Inc. 5. Scope of Business operation Engineering, detailing, manufacturing and quality compliance activities are proposed to be led by Interarch from India. ER Steel will primarily support market development, customer relationships, sales and marketing activities in USA & Canadian markets. 6. Details of consideration paid The initial funding required by the JV /received in agreement / $; compantyo procure land, to undertake the development and operationalisation of the Business, and to meet tial working capital requirements is expected to be [INR 80,00,00,000 (Indian Rupees Eighty Crore) An amount equal to 25% (twenty five per cent) of the Initial Cost shall be contributed by way of (a) Incorporation Capital contributed by Interarch; and (b) remittance of Initial Contribution by the Shareholders INTERARCH BUILDING SOLUTIONS LIMITED (Formerly known as Interarch Building Products Limited) Head Office : B-30, Sector 57, Noida - 201301, India. Tel.: +91 120 4170200, CIN: L45201DL1983PLC017029 Bu G Registered Office: Farm No-8, Khasra No. 56/23/2, Dera Mandi Road, Mandi Village,T sil Mehrauli, New Delhi - 110047, India. info@interarchbuildings.com www.interarchbuildings.com The balance 75% (seventy five per cent) of the Initial Cost, being INR [60,00,00,000] (Indian Rupees [Sixty Crores]) shall be contributed by the Shareholders in 3 (three) equal tranches of INR [20,00,00,000] (Indian Rupees [Twenty Crores]) each and such that Interarch and ER Steel contribute the Committed Capital in the Agreed Shareholding Rati (74:26) 7. Significant terms and conditions Equity split: Interarch will hold 76% and of agreemen/ ItV in brief; ER Steel 24% on a fully diluted basis, and the shareholding is intended to remain in that ratio through the staged funding/tranche closings. Funding structure: The parties will make an initial contribution at the Initial Closing, and the balance of the initial cost will be contributed in 3 equal tranches on each relevant tranche closing date, subject to the conditions precedent. Offtake commitment: ER Steel must enter into an Offtake Agreement with the JVCo and purchase a minimum quantity of OWSJ products for distribution and sale in Canada & USA. This is a major commercial assurance for the JV. Governance/formation framework: Interarch will incorporate the JVCo in India, and the JVCo will execute a Deed of Adherence to be bound by the JV terms once incorporated. The agreement also sets the management and regulatory framework for the JVCo. INTERARCH BUILDING SOLUTIONS LIMITED (Formerly known as Interarch Building Products Limited) Head Office : B-30, Sector 57, Noida - 201301, India. Tel.: +91 120 4170200, CIN: L45201DL1983PLC017029 Registered Office: Farm No-8, Khasra No. 56/23/2, Dera Mandi Road, Mandi Village, Tehsil Mehrauli, New Delhi - 110047, India. info@interarchbuildings.com www.interarchbuildings.com 8. Whether the acquisition would fall No. within related party transactions and whether the promoter/ promoter group/ group companies have any interest in the entity being acquired? If yes, nature of interest and details thereof and whether the same is done at “arms length”; 9 Size of the entity(ies); The Total initial investment planned is 80 Crores. Depending on the growth of the business, we have option to expand further. 10 Rationale and benefit expected. Considering ER Steel Inc.’s presence in USA & Canadian market, this JV with ER Steel Inc. for the Design, Manufacturing & Supply of Open Web Steel Joits would open anew market for us. Interarch’s strength in Engineering & manufacturing combined with ER Steel Inc’s knowledge & presence in the target market makes a very strong basis for a successful partnership. In the short term, the plan is to capture 2 to 5% of the market share in the next three years, which opens up a completely new revenue stream for the company. For INTERARCH BUILDING SOLUTIONS LIMITED ARVIND NANDA MANAGING DIRECTOR DIN: 00149426 INTERARCH BUILDING SOLUTIONS LIMITED (Formerly known as Interarch Building Products Limited) Head Office : B-30, Sector 57, Noida - 201301, India. Tl +91 120 4170200, CIN: L4S201DL1983PLCO17029 BUIL%RG Registered Office: Farm No-8, Khasra No. 56/23/2, Dera Mandi Road, Mandi Village, Tehsil Mehrauli, New Delhi - 110047, India. info@interarchbuildings.com www.interarchbuildings.com